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THE DISTRIBUTION OF GORSE AND BROOM ON FOXHALL HEATH G O R S E bushes are mainly found along the footpaths although some have spread towards the centre of the Heath. Broom, too, is found along the paths. Dr. Weiss in his paper " The Dispersal of the Seeds of Gorse and Broom by Ants " proved by experiments thaf ants eat the caruncle or oil body attached to the seeds of both gorse and broom. Since ants are known to move their food and nest materials along footpaths, it seems possible that gorse and broom growing near paths were established by ants. The dispersal near the centre of the heath may have been carried out by explosive dehiscence, although I have found ants' nests even here. There is a network of paths over the heath and no part is very far from a human trackway. Experiments were carried out on Foxhall Heath to determine whether ants would move seeds. Seeds were placed on the paths near the nests of ants. A.—Experiment with seeds of Ulex europaeus. Sept. 14th, 1942. At 3.00 p.m. 13 seeds were placed on the ants' pathway. At 3.15 p.m. 12 seeds remained. At 3.20 p.m. 9 seeds remained. At 3.25 p.m. 5 seeds remained. At 3.30 p.m. 0 seeds remained. B.—Sept. 21st. Seeds of Ulex europaeus were again used. 4.00 p.m. 6 seeds were placed on the pathway. 4.05 p.m. 5 seeds remained. 4.10 p.m. 3 seeds remained. 4.15 p.m. 0 seeds remained. C.—Sept. 28th. Seeds of Cytisus scoparius were used. At 4.30 p.m. 5 seeds were placed on the pathway. At 4.32 p.m. 4 seeds remained. At 4.36 p.m. 3 seeds remained. At 4.41 p.m. 2 seeds remained. At 4.48 p.m. 0 seeds remained. The behaviour of the ants was noted during these experiments. An ant found the gorse seed and tasted the oil body, but had difficulty in manipulating the seed. This ant turned the seed about and held it with its hind legs. Finally it dragged it away. Other ants came, some managed to bite off the caruncle. One appeared to teil of its discovery by touching the antennae of a fellow worker. This rather reminded me of the bee-dance mentioned by Maeterlinck in his " The Life of the Bee." Some ants were quite indifferent to the food and passed unconcernedly on their way. These experiments suggest the possibility of the dispersal of the seeds of gorse and broom by ants. ADA E .



Gorse and Broom on Foxhall Heath  
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