MASS E M E R G E N C E O F T H E EMPEROR D R A G O N F L Y Anax Imperator Linn. There is a pond near Reading which is particularly favoured by this dragonfly, and in 1953 I was invited to photograph the emergence of the insects. Accordingly, on 25th May, I travelled to Reading to meet Dr. P. S. Corbet, who had been carrying out considerable research on this species. The pond is about 80 yards by 20 yards, shallowest at one end and deepening to about four feet at the other, where trees and shrubs overhang the water. The pond is situated on heath land, with many pine and birch trees. Every year some 4,000 A. imperator dragonflies emerge here, and Dr. Corbet, by observing the movements of the larvae in the water, is able to predict fairly closely the date of emergence. As a general rule the larvae leave the water at dusk, and the dragonflies emerge between then and midnight. On the night of 25th May, a fair number emerged, but on the night of 26th, following an intensely hot day, the main emergence occurred, with over 1,000 insects emerging. The number is accurately determined as the exuviae can easily be found and counted on the following day. It was a most extraordinary sight to watch the larvae crawling out of the water, up the stems of shrubs, and up the trunks of trees, sometimes to a height of 15 feet or more. The dragonflies were photographed by flashlight-, in all the stages of the emergence. The insects rest where they have emerged until dawn, when, their wings then ready for flight, they fly away from the pond to spend about ten days right away from water tili they become fully mature. They then return to the pond in order to pair and for the females to lay their eggs in the leaves of water plants. This year, 1957, I was able in June to carry out a long-felt wish to photograph the female Emperor dragonflies laying their eggs. My wife and I spent a day of glorious heat and sunshine at the pond, where, after wading cautiously, waistdeep into the middle, I was able to stalk the dragonflies and take the pictures that I wanted. S.