NOTES ON THE COMMON MAYFLY. 



265 



Surrey, flying in bright sunshine at 3.30 p.m. There was a soft 

 south-west wind blowing, and it was very warm. Only a very 

 small 'hatch,' consisting of males only. A few specimens of 

 E. danica were seen at Brook at 6 p.m., these also being males. 



"May 19th. — Sweetwater, Witley, Surrey. Evidently a 

 considerable 1 hatch ' had taken place during the past hours, 

 judging from the shed nymph-pellicles floating on the water, 

 and there were a considerable number of male flies on the wing 

 at 3 p.m. Their flight was only of short duration, and kept up 

 at intervals of from one to two minutes. During their periods 

 of rest they settled on grass some way from the water ; wind 

 south-west, as before. When walking their pace is slow, and in 

 their movements reminding one very much of that of the Mole- 

 Cricket. Their front legs are seldom used for progression, but 

 held straight in front in a supplicating manner, like those of a 

 Mantis. Just after alighting the caudal setae are spread con- 

 siderably, but closed again directly afterwards. 



"May 21st. — Numbers on the wing at 3.30 p.m. Day very 

 hot, and a slight north-east breeze blowing. The flies seen were 

 of both sexes. After pairing, which was of too short duration to 

 allow of any close observations, the female insect flew on to a 

 high branch of a fir-tree, and remained clinging wings down- 

 ward. The male insect fluttered into the close herbage bordering 

 the pond. From 3.30 p.m. to 5.30 p.m. I was absent from the 

 place, but returned again at 6 p.m., and found swarms of females 

 flying over the water and depositing their eggs. Now perhaps it 

 is right to assume that some hours must elapse before the im- 

 pregnated eggs are fit to be deposited, as, after pairing, I have 

 never seen the female fly direct to the water, but, as before stated, 

 fly up on to a tree. I had good opportunities for watching the 

 female deposit her eggs, which was effected thus : flying slightly 

 above the water she would dip every now and then as if seeking a 

 suitable place. When this was found she would alight bodily on 

 the water and jerk her abdomen up and down, wings and caudal 

 setae being widely spread. She then curved the end of her 

 abdomen downwards, and with the three setae spread out to their 

 fullest extent and just resting on the water the eggs were dropped 

 in a shower, which looked like minute white substances resem- 

 bling the roe of a fish. The wings at this time were held clear 



