2. The size of your organization is inverselycorrelated to the amount of revenue yourbusiness can derive.
Ans: False
3. Hiring a salesperson is more attractive than increasing support staff in terms of revenue generated.
Ans: True
4. Your team members can help you evaluate the feedback you receive from outsiders.
Ans: True
5. Over 95% of entrepreneurs in the US report that their team members are the major source of seed financing.
Ans: False
6. A business superstar is unlikely to possess all the business skills needed for long term success.
Ans: True
7. Analysisof your resume will help you decide what team members you need.
Ans: True
8. Entrepreneurs who areoverly conscious of their own weaknesses are more likely to fail.
Ans: True
9. Myers-Briggs personality type indicator can accurately predict an individual’s likelihood for success in an entrepreneurial endeavor.
Ans: False
10. Certain personalities are better suited for entrepreneurship than others.
Ans: False
11. It can be a mistake to quickly grow a business big.
Ans: True
12. Early stage companies are hierarchal.
Ans: False
13. Co-founders of a start-up should work on every task and decision together.
Ans: False
14. It is more common for teams to self-destruct because of personal conflicts than for lack of funding.
Ans: True
15. If you decide to start a venture, you should notify your current employer as soon as possible.
Ans: True
16. After you have started a business, it is a bad idea to combine your new job with working fulltime elsewhere.
Ans: False
17. If employees own a part of your company, they work better.
Ans: True
18. In general, it is a good idea to grant founder shares to at least 10 people.
Ans: False
19. Founder shares should be distributed equally between all founders.
Ans: False
20. It is a mistake to distribute all the options to existing employees.
Ans: True
21. Startups should negotiate below-market salaries.
Ans: True
22. You may find an angel investor who will guide you at the early stages of your venture.
Ans: True
23. Free resources cannot substitute for a qualified lawyer.
Ans: False
24. Board members should be encouraged to act in the best interest of just the principal owner.
Ans: False
25. Company culture is incredibly difficult to change after being established.
Ans: True Multiple Choice
1. According to astudy by Babson College and LBS, businesses with growth aspirations plan on employing more than 20 people within the next:
a) 2 Years
b) 3 Years
c) 4 Years
d) 5 Years
e) None of the above
Ans: d
2. How much, according to Robert Morris and Associates, do restaurants generate in net income before taxes on average?
a) ~2%
b) ~5%
c) ~10%
d) ~13%
e) ~17%
Ans: b
3. Which of the following is true about teams?
a) Teams provide constructive feedback for your ideas
b) Teams increase your network exponentially
c) Teams increase your revenue
d) Teams provide you with moral support
e) All of the above
Ans: e
4. Which of the following should the founder of the venture do first when deciding whether to be the CEO of his/her company?
a) Ask for his/her friends opinion
b) Take at least three personality tests
c) Review his/her resume
d) Work as a hired manager for at least 4 years
e) Consult with his/her team members
Ans: c
5. Who are most likely to launch their own businesses?
a) People overly conscious of their own weaknesses
b) People benchmarking their competitors’ strengths
c) People objectively evaluating their strengths and weaknesses
d) People emphasizing their strengths
e) People oblivious to their own weaknesses
Ans: e
6. Which of the following personalities is best suited for entrepreneurship?
a) Analytical
b) Driver
c) Expressive
d) Amiable
e) None of the above
Ans: e
7. What is the ideal combination of team members?
a) People of different ages
b) People having different backgrounds
c) People of different gender
d) People having different origins
e) People from different countries
Ans: b
8. According to Inc. 500, what part of entrepreneurs start business with their friends or family members?
a) Less than 5%
b) ~10%
c) ~20%
d) ~40%
e) Morethan 65%
Ans: d
9. What does the movie startup.comdemonstrate?
a) How outside financing contributes to equity
b) How expensive lawyers can be
c) How working together can affect the relationship of two lifelong friends
d) How much Government is willing to help young entrepreneurs
e) None of the above
Ans: c
10. What opportunities can a young company offer its potential team members?
a) Growth into higher management positions
b) Above average market salaries
c) More attractive social benefits packages
d) Secure and stable job
e) All of the above
Ans: a
11. Which of the following should an entrepreneur do when creating a venture?
a) Expropriate his/her current employer’s intellectual property
b) Use his/her employer’s resources for the new venture
c) Notify his/her current employer about the intention to create a new venture
d) Spend all his/her time working for the new venture
e) Live off their savings or their spouse’s income
Ans: c
12. According to the chapter, which of the following is not an acceptable means of maintaining an entrepreneurs’ personal cash flow?
a) Working full-time and devoting time to the new venture
b) Working part-time and devoting time to the new venture
c) Living off personal savings
d) Living for his/her spouses’ income
e) All of the above are acceptable
Ans: e
13. Which of the following is not a reason for distributing equity among employees?
a) New companies often can’t pay market rates for salary and wages
b) Including some equity in the compensation package aligns the employee with the company
c) The sense of ownership boosts morale
d) Distributing equity among employees reduces the risk of hostile takeover
e) Having some equity, the team sticks together during the rough times in the early launch phase
Ans: d
14. None of the following tools are usually considered an equivalent of “sweat equity” except:
a) Founder shares
b) Option pool
c) Restricted stock
d) Stock appreciation rights
e) Phantom stock
Ans: a
15. What are the disadvantages of distributing founder shares equally among all co-founders?
a) It slows down the decision making process
b) CEO may be doing more than his/her peers, but have less potential upside
c) Such distribution makes unwanted acquisitions easy
d) A and B
e) A and C
Ans: a
16. Options give the holder the right to:
a) Increase the number of the company shares he/she is allowed to purchase
b) Buy a share in the company at a below-market rate
c) Secure a salary increase on a regular basis
d) Sell his/her stocks to the company at a rate much higher than the market price
e) Refund the money he/she paid for a part of the company’s equity
Ans: b
17. Restricted stock is actual shares that
a) Maynot vote
b) Are cheap
c) Vest over time
d) Have reduced interest rate
e) Are most commonlyused as a means of equity compensation
Ans: c
18. Stock appreciation rights accrue to employees only if:
a) The stock price decreases
b) Combined with options
c) Employee performs well
d) The stock price increases
e) None of the above
Ans: d
19. All of the following is true about the phantom stocks except:
a) They are expensed over the vesting period
b) They do give employees the right to own equity
c) The company needs cash when phantom stocks are exercised
d) They grant the holders additional voting power
e) They lower the dilution effect
Ans: d
20. Which of the following are not considered external team members?
a) Board of Directors
b) Lawyers
c) Accountants
d) Angel investors
e) Foreign partners
Ans: e
21. What is the minimum expected level of lawyers’ fees?
a) $50/hour
b) $100/hour
c) $150/hour
d) $200/hour
e) $250/hour
Ans: c
22. Inappropriatesources of members for Board of Advisors are:
a) Shareholders’ representatives
b) Entrepreneurs
c) Individual with insights about your target customer
d) Your professors
e) Venture capitalists
Ans: a
23. Which of the following is true about a company’s culture?
a) A company’s cultureis relatively easy to change
b) As a company grows, it’s common for the culture to evolve
c) More team members will fit your company’s culture over time
d) Problems with the team do not arise in companies with strong culture
e) All elements of a company’s culture constantly change
Ans: b
24. By making your team members work long hours you put them under the risk of:
a) Burnout
b) Family pressure
c) Stress
d) Reducedefficiency
e) All of the above
Ans: e
25. You are less likely to resolve an interpersonal conflict in your team by:
a) Firing one of the parties
b) Hiring an outside expert who is perceived as a neutral party
c) Explaining it to the parties that they reduce the team’s efficiency
d) Mediating between the parties
e) Transferring one of the parties to another team
Ans: c Essay
1. Explain why solo entrepreneurs are generally less successful than team players.
Ans:
First, a team enables the entrepreneur to do more than he or she could on her own.
Solo entrepreneurs suffer from a number of shortcomings, including a limited perspective, little moral support, and a small network.
Solo entrepreneurs often fail to get feedback on their idea that could help them better match customer needs and thereby increase product demand.
If you build your team wisely you will gain access to a broader range of contacts that can help your business.
A team alsorounds out the skill set needed to launch a business.
2. What are some of the methods used to identify an entrepreneur’s strengths and weaknesses?
Ans:
Self-assessment –update your resume.
Conducting feedback analysis –compare your predictions of asignificant action to the actual outcome.
Talk to those people in your sphere of influence, people who know you well and whom you respect.
Take a psychological or a personality test.
3. What valuable contributions can your team members bring to your company?
Ans:
Professional knowledge
Money required to start a business
Resourses/contacts
Managerial skills
4. How can you identify the best co-founders and team members in your start-up?
Ans:
Everyone contributes to the business.
You can work together without personal issues standing between you.
Your team members are excited about the venture itself and its future.
5. Describe pros and cons of the dual job strategy at the early stages of the venture.
Ans:
Pros: you have a source of cash needed for you to live while you are developing your idea; you can keep the job if you see that your new start-up is not doing so well
Cons: dual job means that you’ll have to work over nights and weekends; you can’t use your current company’s resources and compete with it until you quit; you can’t launch a new start-up while working elsewhere full-time
6. Give definitions of some of the compensation used to make your start-up attractive for valuable team members.
Ans:
Founder Shares
Option pool
Restricted stock
Stock appreciation rights
Phantom stock
7. Explain why it is beneficial for the owner to use vesting concept of compensation.
Ans:
Vesting basically means that people earn their shares or options over time, usually over four or more years.
By introducing vesting concept, the company makes it more attractive for key employees to stay with the company as it grows.
Also, the company may prevent its employeesfromsellingtheir shares–they may be obliged to offer the stock to the company first.
8. Who is it better to invite to work in the Board of Advisors of your firm and why?
Ans:
Professors –for their fundamental knowledge
Current and former entrepreneurs –for their practical knowledge and experience
Professional investors such as venture capitalists and angels –for network extension and fund raising
Suppliers for your firm –for insights about new customer and market trends
9. Why arelawyers and accountants considered to be external members of your team?
Ans:
Your lawyer will most likely work very closely with you and will know everything about your company. Therefore, it is essential that he offers a highly customized service to you and his contributions are usually asimportant as those from your team members, especially in terms ofpreventing possible damage to the venture.
An accountant is a trained business professional who can help you analyze the strengths and weaknesses of your company’s financial performance. He or she may be able to help you find ways to improve cash flow, strengthen margins, and identify tax benefits that can save you money down the road.
Both lawyers and accountants represent another spoke in your network, as both groups frequently have a long list of business and professional contacts. This can include everything from potential partners and customers to angel investor networks and venture capital firms.
10. Three major problems your team may face are burnout, interpersonal conflicts and family pressure. Describe how you can prevent and overcome them.
Ans:
Listen to each team member, not only about the progress of their assignments, but also about the stresses they may be feeling.
You can introduce stress-relieving activities, or bonding experiences such as the Friday happy hour, or the lunchtime basketball game.
Counsel your team members to set expectations for their families even before they join your team.
Resolve interpersonal conflicts as quickly as possible or they may escalate to the point where they are destructive –mediate, hire an outside expert or fire one of the arguing parties.
Random
documents with unrelated content Scribd suggests to you:
F . 377. Diagrammatic section of the abdomen of Acridium tartaricum, showing the ventral septum (i, p, l) contracted, and (i, k, l) stretched out; oh, rib-like lateral processes of the urite; f, ganglia; b, heart, with its suspensorium (a); c, fat tissue in the pericardial tissue sinus; d, dorsal septum or diaphragm contracted. q, extended; g, fatbody; e, muscular part of diaphragm; no, expiration, hm, inspiration, muscle. This and Figs. 375, 376, after Graber.
The supraspinal vessel.—In many insects there is a ventral heart acting on the heart’s blood as an aspirator, or more correctly a
ventral sinus lying on the nervous cord, and closed by a pulsating diaphragm. This was discovered by Réaumur in the larva of a fly, and by Graber in the dragon-fly and locusts (Acrydiidæ). A glance at Figs. 375 and 376 will save a long description. The ventral wall forms a furrow, and between its borders (Fig. 377, e) extends the diaphragm. During the contraction of the muscles—and this, here, acts from before backwards—the membrane rises up and makes a cavity for the blood, which passes backwards over the nervous cord. The dorsal and ventral sinuses together thus bring about a closed circulation.
It thus appears that the insects are well provided with the means of distribution of their nutritive fluid, and that the blood is kept continually fresh and rich in oxygen. (Graber.)
The aorta.—While the heart is mostly situated within the abdomen, it is continued into the thorax and the head as a simple, non-pulsating tube, called the aorta. In Sphinx the aorta, as described by Newport, begins at the anterior part of the 1st abdominal segment, where it bends downwards to pass under the metaphragma and enter the thorax; it then ascends again between the great longitudinal dorsal muscles of the wings, and passes onwards until it arrives at the posterior margin of the pronotum; it then again descends and continues its course along the upper surface of the œsophagus, with which it passes beneath the brain, in front of which and immediately above the pharynx, it divides into two branches, each of which subdivides. Newport, however, overlooked a thoracic enlargement of the aorta called by Burgess the “aortal chamber” (Fig. 310, a, c).
“In Sphinx and Vanessa urticæ, immediately after the aorta has passed beneath the cerebrum, it gives off laterally two large trunks, which are each equal in capacity to about one-third of the main vessel. These pass one on each side of the head, and are divided into three branches which are directed backwards, but have not been traced farther in consequence of their extreme delicacy. Anterior to these trunks are two smaller ones which appear to be given to the parts of the mouth and antennæ, and nearer the median line are two others which are the continuations of the aorta. These pass upwards, and are lost in the integument. The whole of these parts are so exceedingly delicate that we have not, as yet, been able to follow them beyond their origin at the termination of the aorta, but believe them to be continuous, with very delicate, circulatory passages along the course of the tracheal vessels. It is in the head alone that the aorta is divided into branches, since, throughout its whole course from the abdomen, it is one continuous vessel, neither
F . 378. A, last three abdominal segments and bases of the three caudal processes of Cloëon dipterum: r, dorsal vessel; kl, ostia; k, special terminal chamber of the dorsal vessel with its entrance a; b, blood-vessel of the left caudal process. B, 26th joint of the left caudal appendage from below: b, a portion of the blood-vessel; o, orifice in the latter. After Zimmermann, from Sharp.
giving off branches, nor possessing lateral muscles, auricular orifices, or separate chambers.” (Newport, art. Insecta, p. 978.)
Dogiel observed in the transparent larva of Corethra plumicornis that the aorta extends only to the hinder border of the brain. Here it divides into two lamellæ, each of which independently extends farther on. One lamella is seen under the brain and under the eye, the other reaches near the eye. The lamellæ are tied to the integument by threads. At the point of division of the aorta is an opening. (Kolbe.)
True blood-vessels appear to exist in the caudal appendages of the May-flies, as the heart appears to divide and pass directly into them (Fig. 378). The last chamber of the heart diminishes in size at the end of the body, and then divides into three delicate tubular vessels which pass into the three caudal appendages, and extend to the end of each one, along the upper side. While the valves of the heart, in all insects, are directed anteriorly because the blood flows from behind, in the larva of the Ephemeridæ the valves of the last chamber of the heart are directed backwards, because from this chamber the blood flows in the opposite direction, i.e. into the caudal appendages. During the contraction of the heart, the elongated section of the same in the last abdominal segment receives a part of the mass of blood contained in the last chamber, which is driven by independent contractions into the caudal appendages. These vessels have openings before the end through which the blood enters into the cavity of the appendages, and can also pass back, in order to be taken up by the body cavity. It is possible that these blood-vessels stand in direct relation to respiration. (Zimmermann, Creutzburg, in Kolbe, p. 544.)
The pericardial cells. Along the heart, on both sides, occur the so-called pericardial cells, which differ from the fat-cells, and also the peritracheal cells of Frenzel, and are mostly arranged in linear series, which have a close relation to the circulation of the blood. In the larva of Chironomus, they lie in groups; in that of Culex, they are arranged segmentally. In caterpillars, these pericardial cells are not situated in the region of the heart, but are arranged linearly on the side, and form a network of granulated cells situated between the fat-bodies. Other rows of these cells are situated near the stigmata and the main lateral tracheæ. (Kolbe.)
According to Kowalevsky, the pericardial cells, and the garland-shaped, cellular cord consist of cells, whose function it is to purify the blood, and to remove the foreign or injurious matters mingled with the blood.
Ampulla-like blood circulation in the head. In the head of the cockroach occurs, according to Pawlowa, a contractile vascular sac at the base of each antenna. The cavity has a valvular communication with the blood space below and in front of the brain, and muscle-fibres effect systole and diastole. Each sac is beyond doubt an independently active part of the circulatory system. These organs also occur in Locusta and other Acrydiidæ, and Selvatico has described similar structures in Bombyx mori and certain other Lepidoptera.
F . 379. Diagram of the circulatory organs in the head of the cockroach, seen from above: A, ampulla; V, antennal vessel; M, chief muscular cord; m, muscular band; Bs, wall of the blood sinus; am, opening of the aorta (a); rg, anterior sympathetic or visceral ganglion; hg, hinder visceral ganglion; F, F, facetted eyes; o, vestigial ocellus; G, G, brain; S, œsophagus. After Pawlowa.
Pulsatile organs of the legs. Accessory to the circulation is a special system of pulsatile organs in the three pairs of legs of Nepidæ, generally situated in the tibia just below its articulation with the femur, but in the fore legs of Ranatra, in the clasp-joint or tarsus, just below its articulation with the tibia. First observed by Behn (1835), Locy has studied the organ (Fig. 380) in Corixa, Notonecta, Gerris, besides the Nepidæ. It is a whip-like structure attached at both ends, with fibres extending upward and backward to the integument of the leg, separate from the muscular fibres and does not involve them in its motions, and is not affected by the muscles themselves. “As the blood-corpuscles flow near the pulsating body they move faster, and around the organ itself there is a whirlpool of motion.” The beating of these organs aids the circulation in both directions, and when the motion ceases, the blood-currents in the legs stop; the rate of the pulsating organ is always faster than that of the heart, and the action is automatic.
F . 380. Pulsating organs in Hemiptera: A, Belostoma nymph, B, legs of Corixa. C, Ranatra, adult, to show the exceptional position of the pulsating organ in the fore legs. D, pulsatile organ in tibia of Ranatra. After Locy.
b. The blood
The blood of insects, as in other invertebrates, differs from that of the higher animals in having no red corpuscles. It is a thin fluid, a mixture of blood (serum) and chyle, usually colorless, but sometimes yellowish or reddish, which contains pale amœboid corpuscles corresponding to the white corpuscles (leucocytes) of the vertebrates, though they are relatively less numerous in the blood of insects. The yellow fluid expelled from the joints of certain beetles (Coccinella, Timarcha, and the Meloidæ) is, according to Leydig, only the serum of the blood. In phytophagous insects the blood is colored greenish by the chlorophyll set free during digestion. The blood of Deilephila euphorbia is colored an intense olive-green, and that of Cossus ligniperda is pale yellow. (Urech.) The blood of case-worms (Trichoptera) is greenish. In some insects it is brownish or violet. The serum is the principal bearer of the coloring material, yet Graber has shown that in certain insects the corpuscles are more or less beset with bright yellow or red fat-globules, so as to give the same hue to the blood.
The leucocytes.—The corpuscles are usually elongated, oval, or flattened oat-shaped, with a rounded nucleus, or are often amœbiform; and they are occasionally seen undergoing self-division. When about to die the corpuscles become amœbiform or starshaped. (Cattaneo.) Their number varies with the developmental stage of the insect, and in larvæ increases as they grow, becoming most abundant shortly before pupation. The blood diminishes in quantity in the pupal stage, and becomes still less abundant in the imago. (Landois.) The quantity also varies with the nutrition of the insect, and after a few days’ starvation nearly all the blood is absorbed. Crystals may be obtained by evaporating a drop of the blood without pressure; they form radiating clusters of pointed needles. The freshly drawn blood is slightly alkaline. (Miall and Denny.)
The size of the corpuscles has been ascertained by Graber, who found that the diameter of the circular blood-disks of the leaf-beetle, Lina populi, is 0.006 mm.; of Cetonia aurata and Zabrus gibbus, 0.008 to 0.01 mm.; and those of certain Orthoptera (Decticus verrucivorus, Ephippiger vitium and Œdipoda cœrulescens), 0.011 to 0.014 mm. The longest diameter of the elongated corpuscles of Carabus cancellatus is 0.008 mm.; of Gryllus campestris, Locusta viridissima, Cossus ligniperda, Sphinx ligustri (pupa), and others, 0.008 to 0.01 mm.; of Caloptenus italicus, Saturnia pyri, Anax formosus, and others, 0.011 to 0.014 mm.; of Ephippiger vitium, Œdipoda cœrulescens, Pezotettix mendax, Zabrus
gibbus, Phryganea, and others, 0.012 to 0.022 mm.; in Stenobothrus donatus and variabilis, 0.012 to 0.035 mm. The largest known are those of Melolontha vulgaris, which measure from 0.027 to 0.03 mm.
F . 381. Blood corpuscles, or leucocytes, of insects: A, a-g, of Stenobothrus dorsatus (the same forms occur in most Orthoptera and in other insects). B, a, leucocyte of the same insect with the nucleus brought out by ether; b, another of serpentine shape. C, leucocytes of the same insect after a longer stay in ether. D, leucocytes of the same after being in glycerine 14 days. After Graber.
As regards the nature of the corpuscles, Graber concludes that they are more like the cells of the fat-bodies than genuine cells. That they are not true cells is shown by the fact that after remaining in their normal condition a long time they finally coalesce and form cords. After shrivelling, or after the blood has been subjected to different kinds of treatment, the nucleus is clearly brought out (Fig. 381).
Besides the blood corpuscles there have been detected in the blood round bodies which are regarded as fat-cells. They are circular, and for the most part larger than the blood corpuscles, have a sharp, even, dark outline, and an invariably circular nucleus. (Kolbe.)
The blood of Meloe, besides the amœboid corpuscles, according to Cuénot, contains abundant fibrinogen, which forms a clot; a pigment (uranidine), which is oxidized and precipitated when exposed to the air; a dissolved albuminoid (hæmoxanthine), which has both a respiratory and nutritive function; and, finally, dissolved cantharidine.
The corpuscles arise from tissues which are very similar to the fat-bodies, and which, at given times, separate into cells. The position of these tissues is not always the same in different insects. In caterpillars, they occur in the thorax, near the germs of the wings; in the saw-flies (Lyda), in all parts of the thorax and abdomen;
in larval flies (Musca), in the end of the abdomen, just in front of the large terminal stigmata. The place where the blood corpuscles are formed is usually near, or in relation with, the fat-bodies. But while the fat-bodies mostly serve as the material for the formation of the blood-building tissues, in caterpillars the tracheal matrix also, and, in dipterous larvæ, the hypodermis serve this purpose. (Cæsar Schaeffer in Kolbe. See also Wielowiejski, Ueber das Blutgewebe.)
Other substances occur in the blood of insects. Landois (1864) demonstrated the existence of egg albumen, globulin, fibrin, and iron in the blood of caterpillars. Poulton found that the blood of caterpillars often contained chlorophyll and xanthophyll derived from their food plants. A. G. Mayer has recently found that the blood (hæmolymph) of the pupæ of Saturniidæ (Callosamia promethea) contains egg albumin, globulin, fibrin, xanthophyll, and orthophosphoric acid, and Oenslager has determined that iron, potassium, and sodium are also present. (Mayer.)
c. The circulation of the blood
Every part of the body and its appendages is bathed by the blood, which circulates in the wings of insects freshly emerged from the nymph or pupal state, and even courses through the scales of Lepidoptera, as discovered by Jaeger (Isis, 1837).
In describing the mechanism of the heart we have already considered in a general way the mode of circulation of the blood.
The heart pumping the blood into the aorta, the nutritive fluid passes out and returns along each side of the body; distinct, smaller streams passing into the antennæ, the legs, wings (of certain insects), and into the abdominal appendages when they are present. All this may readily be observed in transparent aquatic insects, such as larval Ephemeræ, dragon-flies, etc., kept alive for the purpose under the microscope in the animalcule box.
Carus, in 1827, first discovered the fact of a complete circulation of the blood, in the larva of Ephemera. He saw the blood issuing in several streams from the end of the aorta in the head and returning in currents which entered the base of the antennæ and limbs in which it formed loops, and then flowing into the abdomen, entered the posterior end of the heart. Wagner (Isis, 1832) confirmed these observations, adding one of his own, that the blood flows backward in two venous currents, one at the sides of the body and intestine, and the other alongside of the heart itself, and that the blood not
only entered at the end of the heart, but also at the sides of each segment, at the position of the valves discovered by StrausDürckheim.
Newport maintains that the course of the blood is in any part of the body, as well as in the wings, almost invariably in immediate connection with the course of the tracheæ, for the reason that “the currents of blood in the body of an insect are often in the vicinity of the great tracheal vessels, both in their longitudinal and transverse direction across the segments.”
The circulation of the blood in the wings directly after the exuviation of the nymph or pupa skin, and before they become dry, has been proved by several observers. As stated by Newport, the socalled “veins” or “nervures” of the wings consist of tracheæ lying in a hollow cavity, the peritracheal space being situated chiefly under and on each side of the trachea.
F . 382. Circulation of the blood in hind wing of Periplaneta orientalis: the arrows indicate the usual direction of the blood currents. After Moseley.
Newport gives the following summary of the observations of the early observers, to which we add the observations of Moseley. “A motion of the fluids has been seen by Carus in wings of recently developed Libellulidæ, Ephemera lutea and E. marginata, and Chrysopa perla; among the Coleoptera, in the elytra and wings of Lampyris italica and L. splendidula, Melolontha solstitialis and Dytiscus.” Ehrenberg saw it in Mantis, and Wagner in the young of Nepa cinerea and Cimex lectularius. Carus detected a circulation in the pupal wings of some Lepidoptera, and Bowerbank witnessed it in a Noctuid (Phlogophora meticulosa); Burmeister observed it in Eristalis tenax and E. nemorum, and Mr. Tyrrel in Musca domestica, but it has not been observed in the wings of Hymenoptera.
Bowerbank observed that in the lower wing of Chrysopa perla the blood passes from the base of the wing along the costal, post-costal, and externo-medial veins, outwards to the apex of the wing, giving off smaller currents in its course, and that it returns along the anal vein to the thorax. He found that the larger
veins, 1 408 in. in diameter, contained tracheæ which only measured 1 2222 of an inch in diameter; but in others the tracheæ measured 1 1340, while the cavity measured only 1 500 of an inch. He states, also, that the tracheæ very rarely give off branches while passing along the main veins, and that they lie along the canals in a tortuous course. (Newport, art. Insecta, p. 980.)
Bowerbank, also, in his observations on the circulation in the wings of Chrysopa, “used every endeavor to discover, if possible, whether the blood has proper vessels, or only occupied the internal cavities of the canals; and that he is convinced that the latter is the case, as he could frequently perceive the particles not only surrounding all parts of the tracheæ, and occupying the whole of the internal diameter of the canals, but that it frequently happens that globules experienced a momentary stoppage in their progress, occasioned by their friction against the curved surface of the tracheæ, which sometimes gave them a rotatory motion.”
Moseley found, owing to the large size and number of the corpuscles, that the circulation of the blood in the wings of insects is most easily observed in the cockroach, especially the hind wings. As seen in Moseley’s figure, the blood flows outward from the body through the larger veins (I and II) of the front edge of the wings, which he calls the main arteries of the wings, and more generally returns to the body through the veins in the middle of the wing; the blood also flows out from the body through the inner longitudinal veins (those behind vein IV), and the blood is also seen to flow through some of the small crossveins. Fig. 383 shows one of the main trunks during active circulation. The corpuscles change their form readily, “the spindle-shaped ones doubling up in order to pass crossways through a narrow aperture.... In the irregularly formed corpuscles, which seem to represent leucocytes amœboid movements were observed.... Corpuscles pass freely above and under the tracheæ, showing that these latter lie free in the vessels.” The hypodermis lining the vessels is best seen in the small transverse veins.
F . 383. Parts of a vein of the cockroach, showing the nerve (n) by the side of the trachea (tr); c, blood corpuscles. After Moseley.
The pulse or heart-beat of insects varies in rapidity in different insects, rising at times of excitement, as Newport noticed in Anthophora retusa, to 142 beats in a minute.
When an insect, as, for example, a tineid caterpillar, has been enclosed in a tight box for a day or more, the pulsations of the heart are very languid and slow, but soon, on giving it air, the pulsations
will, as we have observed, rise in frequency to about 60 a minute, Herold observed 30 to 40 in a minute in a fully-grown silkworm, and from 46 to 48 in a much younger one. Suckow observed but 30 a minute in a full-grown caterpillar of Gastropacha pini, and 18 only in its pupa.
In a series of observations made by Newport on Sphinx ligustri from the fourth day after hatching from the egg until the perfect insect was developed, he found that before the larva cast its first skin the mean number of pulsations, in a state of moderate activity and quietude, was about 82 or 83 a minute; before the second moult 89, while before the third casting it had sunk down to 63; and before its fourth to 45, while, before leaving its fourth stage, and before it had ceased to feed, preparatory to pupating, the pulse was not more than 39. “Thus the number gradually decreases during the growing larva state, but the force of the circulation is very much augmented. Now when the insect is in a state of perfect rest, previously to changing its skin, the number is pretty nearly equal at each period, being about 30. When the insect has passed into the pupa state it sinks down to 22, and subsequently to 10 or 12, and after that, during the period of hibernation, it almost entirely ceases. But when the same insect which we had watched from its earliest condition was developed into the perfect state in May of the following spring, the number of pulsations, after the insect had been for some time excited in flight around the room, amounted to from 110 to 139; and when the same insect was in a state of repose, to from 41 to 50. When, however, the great business of life, the continuation of the species, has been accomplished, or when the insect is exhausted, and perishing through want of food or other causes, the number of pulsations gradually diminishes, until the motions of the heart are almost imperceptible.” Insects, then, he remarks, do not deviate from other animals in regard to their vital phenomena, though it has been wrongly imagined that the nutrient and circulatory functions are less active in the perfect than in the larval condition.
The heart of a larval Gastrus equi taken the day previous from a horse’s stomach beat from 40 to 44 times a minute (Scheiber); while Schröder van der Kolk observed only 30 beats in the same kind of maggot.
In the larva of Corethra, while at rest, the heart contracts from 12 to 16 or 18 times a minute, but when active the number rises to 22. The systole and diastole last from 5 to 6 minutes. (Dogiel.)
Temperature also affects the pulsations, as they increase in frequency with a rise and decrease with a fall in temperature.
Influence of electricity. The influence of electricity on the action of the insect’s heart, from Dogiel’s experiments, is such as to cause an acceleration in the frequency of the beats, while an increase in the strength of the electric currents either diminishes the frequency of the beats or entirely stops the heart’s action. A violent excitation with the induction current causes a systole when the heart’s action has stopped for a long time; and if the excitation lasts uninterruptedly, then
the contractions after a while become noticeable, according to the strength of the current. In such a case there are, however, interruptions in the regularity, strength, and order of the contractions. (Kolbe.)
Effects of poisons on the pulsations. Dogiel has also experimented on the influence of poisons in the form of vapor or as liquid solutions on the pulsations of insects, which is much as in vertebrates. The application of carbonic oxide to the larva of Corethra, whose heart one minute previous to the poisoning beat 15 times a minute, accelerated the heart-beats in about 55 minutes to 25 pulsations in a minute. Afterwards there was a retardation in the pulse to the normal beat. Carbonic acid had a similar effect.
The following results obtained by Dogiel are somewhat as tabulated by Kolbe:—
I. Substances which cause the pulsations of the heart to accelerate.
a. An induction current of electricity, acting feebly.
b. Ammonia, acting feebly.
c. Ethyl ether, acting feebly.
d. Oxalic acid, acting feebly.
e. Carbolic acid, acting feebly.
f. Potassium nitrate, acting feebly.
g. Aconite, acting feebly.
II. Substances retarding the heart’s action.
a. An induction current of electricity, acting energetically.
b. Ammonia, acting energetically.
c. Ethyl ether, acting energetically.
d. Oxalic acid, acting energetically.
e. Carbolic acid, acting energetically.
f. Veratrine, acting energetically.
g. Atropine, acting energetically.
h. Aconitine, acting energetically.
i. Potassium nitrate, acting energetically.
g. Ethyl alcohol.
h. Chloroform.
i. Carbonic oxide.
j. Carbonic acid.
k. Sulphuretted hydrogen.
III. Substances whose action is indifferent.
1. Muscarine.
2. Curare.
3. Atropine, acting slowly.
4. Strychnine.
The above-named substances comprise those which in the vertebrates effect a change in the activity of the motor nerve-ganglia of the heart and the muscular fibres. Hence it follows that the heart of the larval Corethra consists of muscular fibres provided with ganglia, and that the contractions of the muscular fibres are provoked through the agency of the ganglia. But since muscarine, atropine, and curare, whose influence in stopping the heart’s action of vertebrates is known, in insects either have no action or only make the pulsations slower; it seems to follow that the heart of the larval Corethra possesses no similar apparatus for lessening the heart’s action, and this is also confirmed by anatomical studies. On the contrary, aconite acts, as we must from observations conclude, exclusively on the motor centres and the muscles, but not on the apparatus for lessening the heart’s action, which, as has been remarked, is not present in the larval Corethra. (Kolbe ex Dogiel.)
Dewitz has discovered an onward movement of the blood corpuscles, somewhat independent of the general circulation. This independent motion of the blood corpuscles is not only a creeping one like the amœboid motion of the white corpuscles of vertebrates, but they have besides a peculiar swimming movement. Dewitz noticed this in the hind wings of a recently emerged meal-worm beetle (Tenebrio molitor), still white and soft, after they had been cut off. The tissues forming the matrix within the wings constitute a network filled with blood. The current of blood within the wing thus cut off may be stopped flowing by a tap on the firmly clamped object-bearer on which the wing is placed, or by drawing it by an apparatus described by the same author, to incite in one way or another the blood corpuscles to swim forwards. When a corpuscle is disposed to move, we see it first stirring restlessly, or wabbling about, in this way changing its form; then it moves forwards, and does not come to a standstill. If it remains still there, after a while, by tapping, it begins again its movements.
“Should one yet doubt the fact of this spontaneous movement of the blood corpuscles, he will surely be convinced of its correctness by observing the so-tospeak reluctantly springing motion of a blood corpuscle in the wing of Tenebrio molitor with the simultaneous change of appearance and shape of the corpuscle.”
This spontaneous or independent motion of the blood corpuscles is also produced by the heating apparatus. As soon as the corpuscles lie still in the severed wing and they are warmed, the corpuscles begin to pass through the meshes of the tissue. When cooled, the motion ceases, but as soon as the temperature rises to a certain grade, the corpuscles again move onwards.
To explain this independent motion Dewitz thinks that they take up and then expel the blood-fluid, and in this way cause their motion. This independent motion is necessitated, in order that the stream of blood may become so regulated, that the blood corpuscles shall not be arrested in their course, but even turn back again out of the farther end of the antennæ and limbs. The chief mechanical power for the blood circulation must go on independently of the propulsatorial apparatus and of the heart. (Kolbe.)
LITERATURE ON THE HEART AND ON THE CIRCULATION OF THE BLOOD
a. Anatomy of the organs
Meckel, J. F. Ueber das Rückengefäss der Insekten. (Meckel’s Archiv, i, 1815, pp. 469–476.)
Müller, J. G. De vasi dorsali Insectorum. Berolini, 1816, pp. 22.
Serres, P. Marcel de. Observations sur les usages du vaisseau dorsal ou sur l’influence que le cœur exerce dans l’organisation des animaux articulés, etc. (Ann. du Mus. d’hist. nat., 1818, iv, pp. 149–192, 313–380, 2 Pls.; v, 1819, pp. 59–147, 1 Pl.)
Herold. Physiologische Untersuchungen über das Rückengefäss der Insekten. (Schriften d. Gesellsch. z. Beförderung d. Naturk. in Marburg, 1823, i, pp. 41–107.)
Carus, C. G. Entdeckung eines einfachen vom Herzen aus beschleunigten Blutkreislaufes in den Larven netzilügliger Insekten. Leipzig, 1827, pp. 40, 3 Taf.
—— Fernere Untersuchungen über Blutlauf in Kerfen. (Acta Acad. Leopold. Carol., 1831, xv, pp. 1–18, 1 Taf.)
Stadelmayr, L. Ansichten vom Blutlauf nebst Beobachtungen über das Rückengefäss der Insekten. Diss. München, 1829, pp. 24.
Berthold. Beitrage zur Anatomie, Zoologie und Physiologie. Göttingen, 1831.
Treviranus, G. R. Ueber das Herz der Insekten, dessen Verbindung mit den Eierstocken und ein Bauchgefäss der Lepidopteren. (Zeitschr. f. d. Physiologie, von F. Tiedemann. G. R. u. L. C. Treviranus, 1832, iv, pp. 181–184, 1 Taf.)
—— Beobachtungen aus der Zootomie und Physiologie. Bremen, 1839.
Wagner, R. Beobachtungen über Kreislauf des Blutes und den Bau des Rückengefässes bei den Insekten. (Isis, 1832, iii, p. 30; vii, pp. 320–331, 778–783, Fig.)
Bowerbank, J. S. Observations on the circulation of the blood in insects. (Ent. Mag., 1833, i, pp. 239–244, 1 Pl; also in Müller’s Archiv f. Physiolog., 1834, i, pp. 119–120.)
—— Observations on the circulation of the blood and the distribution of the tracheæ in the wing of Chrysopa perla. (Ent. Mag., 1837, iv, pp. 179–185.)
Jaeger. Ueber die Entdeckung von einer Bewegung in den Schuppen des Schmetterlingsflügel. (Isis, 1837, v, p. 512.)
Behn, W. Découverte d’une circulation de fluide nutritif dans les pattes de plusieurs insectes hémipteres. (Ann. Sc. nat., 1835, Sér. 2, iv, pp. 1–12.)
Newport, G. Insecta, in Todd’s Cyclopædia of Anatomy and Physiology, 1839. London, pp. 853–994. On the circulation of the blood, p. 976, Figs.
Duvernoy, G. L. Résumé sur le fluide nourricier, ses réservoirs et son mouvement dans tout règne animal. (Ann. Sc. nat., 1839, Sér. 2, xii, pp. 300–346.)
Dufour, L. Études anatomiques et physiologiques sur une mouche dans le but d’eclairer l’histoire des metamorphoses et de la prétendue circulation dans les insectes. (Ann. Sc. nat. Zool., Sér. 2, 1841, xvi, pp. 5–14.)
—— Note sur la prétendus circulation dans les insectes. (Compt. rend. Acad., Paris, 1844, xix, pp. 188–189.)
—— Études anatomiques et physiologiques sur une mouche, dans le but d’éclaircir l’histoire des metamorphoses et de prétendue circulation des insectes. (Mém. mathémat. des Savants étrangers, Paris, 1846, ix, pp. 545–628, 1 Pl.)
—— Sur la circulation dans les insectes. Bordeaux, 1849, 8º, pp. 40. (Compt. rend. Acad. Sci., Paris, 1849, xxviii, pp. 28–33, 101–
104, 163–170.)
—— De la circulation du sang et de la nutrition chez les insectes. Bordeaux, 1851. (Act. Soc. Linn., Bordeaux, 1851, xvii, p. 9.)
—— Études anatomiques et physiologiques et observations sur les larves des Libellules, Appareil circulatoire. (Annal. Sci. nat., Sér. 3, Zool., xvii, 1852, pp. 98–101, 1 Pl.)
Schröder van der Kolk, J. S. C. Mémoire sur l’anatomie et physiologie du Gastrus equi. (N. Verhandl. Kl. Nederl. Instit., 11, 1845, pp. 1–155, 13 Pl.)
Nicolet, H. Note sur la circulation du sang chez les Coléoptères. (Ann. Sc. nat., 1847, Sér. 3, vii, pp. 60–64.)
Verloren, C. Mémoire en réponse à la question suivante: éclaircir par des observations nouvelles le phénomène de la circulation dans les insectes, en recherchant si on peut la reconnaître dans les larves de différents ordres de ces animaux. (Mém. couronn. et Mém. d. savants étrang. de l’Acad. Roy. Belgique, xix, 1847.)
Blanchard, E. De la circulation dans les insectes. (Ann. Sc. nat., 1848, Sér. 3, ix, pp. 359–398, 5 Pls.)
—— Sur la circulation du sang chez les insectes et sur la nutrition. (Compt. rend. Acad. Sc., Paris, 1849, xxviii, pp. 76–78; 1851, xxxiii, pp. 367–370.)
—— Nouvelles observations sur la circulation du sang et la nutrition chez les insectes. (Ibid., pp. 371–376.)
Joly, N. Mémoire sur l’existence supposée d’une circulation péritrachéenne chez les insectes. (Ann. Sc. nat. Zool., Sér. 3, 1849, xii, pp. 306–316.)
Bassi, C. A. Rapporto alla sezione di zoologia, anatomia comparata e fisiologia del congresso di Venezia, sul passagio delle materie ingerite nel sistema tracheale degli insetti. (Gazette di Milano, 1847, vi; also Ann. Sc. nat. Zool., Sér. 3, 1851, xv., 362–371.)
Agassiz, Louis. On the circulation of the fluids in insects. (Proceed. Amer. Assoc. Adv. Sc., 1849, pp. 140–143; Ann. Sc. nat. Zool., Sér. 3, xv, 1851, pp. 358–362.)
Leydig, F. Anatomisches und Histiologisches über die Larve von Corethra plumicornis. (Zeitschr. f. wissen. Zool., iii, 1851, pp. 435–451.)
Wedl, C. Ueber das Herz von Menopon pallidum. (Sitzungsber. der k. Akad. d. Wissensch. Wien., 1855, xvii, pp. 173–180.)
Scheiber, S. H. Vergleichende Anatomie und Physiologie der Oestriden Larven. (Sitzungsber. d. k. Akad. d. Wiss. Wien. Math.naturwiss. Cl., xli, 1860, pp. 409–496, 2 Taf.; The circulatory system, pp. 463–490.)
Brauer, Fr. Beitrag zur Kenntnis des Baues und der Funktion der Stigmenplatten der Gastrus-Larven. (Verhdl. d. k. k. zool.-bot. Gesellsch. Wien., xiii, 1863, pp. 133–136.)
Moseley, H. N. On the circulation in the wings of Blatta orientalis and other insects, and on a new method of injecting the vessels of insects. (Quart. Jour. of Micr. Science, xi, n. s., pp. 389–395, 1871, 1 P1.)
Graber, V. Ueber die Blatkörperchen der Insekten. (Sitzber. Akad. Wien. Math.-naturw. Classe, lxiv, 1871, pp. 9–44, 1 Taf.)
—— Vorläufiger Bericht über den propulsatorischen Apparat der Insekten. (Sitzber. d. k. Ak. d. Wiss. Wien., lxv, 1872, pp. 16, 1 Taf.)
—— Ueber den propulsatorischen Apparat der Insekten. (Archiv f. mikroskop. Anatomie, ix, 1873, pp. 129–196, 3 Taf.)
—— Ueber den pulsierenden Bauchsinus der Insekten. (Archiv f. mikroskop. Anat., xii, 1876, pp. 575–582, 1 Taf.)
Grobben, Carl. Über bläschenförmige Sinnesorgane und eine eigenthümliche Herzbildung der Larve von Ptychoptera contaminata L. (Sitzb. k. Akad. Wissensch. Wien., 1875, lxxii, p. 22, 1 Taf.)
Liebe, Otto. Ueber die Respiration der Tracheaten, besonders über den Mechanismus derselben und über die Menge der ausgeatmeten Kohlensäure. Inaug.-Diss. Chemnitz, 1872, pp. 28.
Dogiel, John. Anatomie und Physiologie des Herzens der Larve von Corethra plumicornis. (Mém. Acad. imp. St. Petersbourg, 7
Sér., xxiv, 1877, Nr. 10, pp. 37, 2 Pls.) Separate, Leipzig, Voss.
Bütschli, O. Ein Beitrag zur Kenntnis des Stoffwechsels, insbesondere der Respiration bei den Insekten. (Reichert’s und Du Bois-Reymond’s Archiv f. Anatomie u. Physiologie, 1874, pp. 348–361.)
Béla-Dezso. Ueber den Zusammenhang des Kreislaufs und der respiratorischen Organe bei den Arthropoden. (Zool. Anzeiger, i Jahrg., 1878, p. 274.)
Plateau, F. Communication préliminaire sur les mouvements et l’innervation de l’organe central de la circulation chez les animaux articulés. (Bull. Acad. roy. de Belgique, Sér. 2, xlvi, 1878, pp. 203–212.)
Jaworovski, Ant. Ueber die Entwicklung des Rückengefässes und speziell der Muskulatur bei Chironomus und einigen anderen Insekten. (Sitzgsber. d. k. Akad. d. Wissensch. Wien. Math.-naturwiss. Cl., lxxx, 1879, pp. 238–258.)
Zimmermann, O. Ueber eine eigentümliche Bildung des Rückengefässes bei einigen Ephemeridenlarven. (Zeitschr. f. wissens. Zool., 1880, xxxiv, pp. 404–406.)
Burgess, E. Note on the aorta in lepidopterous insects. (Proc. Bost. Soc. Nat. Hist., xxi, 1881, pp. 153–156, Figs.)
—— Contributions to the anatomy of the milk-weed butterfly, Danais Archippus F. (Anniversary Memoirs Boston Soc. Nat. Hist., 1880, pp. 16, 2 Pls.)
Vayssière, A. Recherches sur l’organisation des larves des Éphémérines. (Ann. Sc. nat. Zool., Sér. 6, xiii, 1882, pp. 1–137, 11 Pls.)
Viallanes, H. Recherches sur l’histologie des insectes et sur les phénomènes histologiques qui accompagnent le développement post-embryonnaire de ces animaux. (Ann. Sc. nat., Sér. 6, xiv, 1882, pp. 1–348, 18 Pls.)
Schimkewitsch, W. Ueber die Identität der Herzbildung bei den wirbel und wirbellosen Tieren. (Zool. Anzeiger, 1885, viii Jahrg., pp. 37–40, Fig.)
—— Noch etwas über die Identität der Herzbildung bei den Metazoen. (Zool. Anzeiger, 1885, pp. 384–386.)
Creutzburg, N. Ueber den Kreislauf der Ephemerenlarven. (Zool. Anzeiger, 1885, pp. 246–248.)
Poletajewa, Olga. Du cœur des insectes. (Zool. Anzeiger, 1886, ix Jahrg., pp. 13–15.)
Selvatico, S. L’aorta nel corsaletto e nel capo della farfalla del bombice del gelso. (Padova, 1887, p. 19, 2 Pls.)
—— Die Aorta im Brustkasten und im Kopfe des Schmetterlings von Bombyx mori. (Zool. Anzeiger, 1887, x Jahrg., pp. 562–563.)
Kowalevsky, A. Ein Beitrag zur Kenntnis der Excretionsorgane. (Biol. Centralbl., 1889, ix, pp. 33–47, 65–76, 127–128.)
Tosi, Alessandro. Osservazioni sulla valvola del cardias in varii generi della famiglia delle Apidi. (Ricerche Lab. Anat. R. Univ. Roma, v, 1895, pp. 5–26, 16 Figs., 3 Pls.)
Pawlowa, Mary. Ueber ampullenartige Blutcirculationsorgane im Kopfe verschiedener Orthopteren. (Zool. Anzeiger, xviii Jahrg., 1895, pp. 7–13, 1 Fig.)
Also the writings of Kolbe.
b. The blood, blood corpuscles, leucocytes, and blood tissue
Wagner, R. Ueber Blutkörperchen bei Regenwürmern, Blutegeln und Dipterenlarven. (Müller’s Archiv f. Anatomie u. Physiologie, 1835, pp. 311–313.)
—— Nachtrage zur vergleichenden Physiologie des Blutes. (Archiv f. Anat. u. Physiologie, 1838.)
Newport, G. On the structure and development of the blood. First series. The development of the blood corpuscle in insects and other invertebrata, and its comparison with that of man and the vertebrata. (Abstr. of the paper in Roy. Soc., 1845, v, pp. 544–546: also in Ann. Mag. Nat. Hist., Ser. 3, 1845, iii, pp. 364–367.)
Landois, H. Beobachtungen über das Blut der Insekten. (Zeitschr. f. wissens. Zool., xiv, 1864, pp. 55–70, 3 Pl.)
——, and L. Landois. Ueber die numerische Entwicklung der histiologischen Elemente d. Insektenkörpers. (Ibid., xv, 1865, pp. 307–327.)
Rollett, A. Zur Kenntnis der Verbreitung des Hämatins. (Sitzgsber. d. k. Akad. d. Wiss. Wien., lxiv, 1871.)
Wielowiejski, H. v. Ueber das Blutgewebe der Insekten. Eine vorläufige Mitteilung. (Zeitschr. f. wissens. Zool., 1886, xliii, pp. 512–536.)
MacMunn, C. A. Researches on myohæmatin and the histohæmatins. (Proc. Roy. Soc. London, 1886, xxxix, pp. 248–252.)
Peyron, J. Sur l’atmosphere interne des insectes comparée à celle des feuilles. (Compt. rend. Acad. Sc., Paris, 1886, cii, pp. 1339–1341.)
Cuénot, L. Études sur le sang, son rôle et sa formation dans la série animale. Part 2, invertébrés; note préliminaire. (Arch. Zool. Expériment., 1888, Sér. 2, v, pp. xliii-xlvii. See also ibid., Sér. 3, 1897, pp. 655, 679–680.)
Dewitz, H. Die selbstandige Fortbewegung der Blutkörperchen der Gliedertiere. (Naturwiss. Rundschau. Braunschweig, 1889, iv Jahrg., pp. 221–222.)
—— Eigenthätige Schwimmbewegung der Blutkörperchen der Gliedertiere. (Zool. Anzeiger, 1889, xii Jahrg., pp. 457–464, Fig.)
Schäffer, C. Beitrage zur Histiologie der Insekten. II, Ueber Blutbildungsherde bei Insektenlarven. (Spengel’s Zool. Jahrbücher Abt. f. Anat. u. Ontogenie, iii, 1889, pp. 626–636, 1 Taf.)
Cattaneo, G. Sulla morfologia delle cellule ameboidi dei Molluschi e Artropodi. (Boll. Sc. Pavia. Anno 11, 1889, p. 59, 2 Pls.)
Wagner, W. A. Ueber die Form der körperlichen Elemente des Blutes bei Arthropoden, Würmern und Echinodermen. (Biolog.
Centralblatt, 1890, x, p. 428.)
Preyer, W. Zur Physiologie des Protoplasma. II, Die Funktionen des Stoffwechsels. Die Saftströmung. (Patanie’s Naturwiss. Wochenschr., 1891, vi, pp. 1–5.)
Cholodkowsky, N. Ueber das Bluten der Cimbiciden-Larven. (Entomologische Miscellen, vi, Horæ Soc. Ent. St. Petersburg, 1897, pp. 352–357, 1 Fig. The fluid thrown out through pores or fissures in the skin is the blood.)
With the writings of Korotaiev, Tichomeroff, Pékarsky, Balbiani, Korotneff, Cuénot, and others.
c. The fat-bodies
Dufour, L. Recherches anatomiques sur les Carabiques et sur plusieurs autres insectes Coléoptères. Du tissu adipeux splanchnique. (Ann. Sc. nat., viii, 1826, pp. 29–35.)
—— Histoire comparative des métamorphoses et de l’anatomie des Cetonia aurata et Dorcus parallelepipedus. Tissu adipeux splanchnique. (Ann. Sc. nat., Zoologie, Sér. 2, 1842, xviii, pp. 178–179.)
Meyer, H. Ueber die Entwicklung des Fettkörpers, der Tracheen und der keimbereitenden Geschlechtsteile bei den Lepidopteren. (Zeitschr. f. wissens. Zool., 1849, i, pp. 175–179, 4 Taf.)
Fabre, J. H. Étude sur le rôle du tissu adipeux dans la sécretion urinaire chez les insectes. (Ann. Sc. nat., Sér. 4, xix, 1862, pp. 351–382.)
Leydig, Fr. Einige Worte über Fettkörper der Arthropoden. (Reichert, u. du Bois-Reymond’s Archiv f. Anat., 1863, pp. 192–203.)
Lindemann, K. Zoologische Skizzen. 1. Struktur des Fettkörpers. (Bull. Soc. Imp. d. Natural. Moscou, 1864, pp. 521–526, 1 Pl.)
Landois, Leonh. Ueber die Funktion des Fettkörpers. (Zeitschr. f. wissens. Zoologie, xv, 1865, pp. 371–372.)
Wielowiejski, H. v. Ueber den Fettkörper von Corethra plumicornis und seine Entwicklung. (Zool. Anzeiger, 1883, vi Jahrg., pp. 318–322.)
—— Ueber das Blutgewebe der Insekten. (Zeitschr. f. wissens. Zool., 1886, xliii, pp. 512–536.)
Kowalevsky, A. O. Sur les organes excréteurs chez les arthropodes terrestres. (Congrès internat. Zool., 2me Sess., pp. 196–205, Moscou, 1892.)
Welcome to our website – the perfect destination for book lovers and knowledge seekers. We believe that every book holds a new world, offering opportunities for learning, discovery, and personal growth. That’s why we are dedicated to bringing you a diverse collection of books, ranging from classic literature and specialized publications to self-development guides and children's books.
More than just a book-buying platform, we strive to be a bridge connecting you with timeless cultural and intellectual values. With an elegant, user-friendly interface and a smart search system, you can quickly find the books that best suit your interests. Additionally, our special promotions and home delivery services help you save time and fully enjoy the joy of reading.
Join us on a journey of knowledge exploration, passion nurturing, and personal growth every day!
