NOTES AND OBSERVATIONS. 225 



captured specimens, so that it is not certain that what he calls the 

 first stage is really such." With regard to the eggs, Dr. Sharp says, 

 on page 441, " The eggs are very numerous, and it is thought may 

 sometimes remain in the water as much as six or seven months 

 before they hatch." 



In view of this want of information, perhaps an experience I had 

 some years ago may be worth recording, although my ignorance at 

 the time of its being anything worth special notice prevented my 

 preserving any of the young in the very first stages, by mounting 

 them as micro slides, or taking detailed notes of formation, which I 

 much regret. I may mention that from 1871 I had been much 

 interested in pond- life in Turkey — had several small aquaria always 

 under observation, and as the larval forms of May-fiies were to be 

 found in every pond and ditch, I kept aquaria well-stocked with 

 them as food for other forms of pond-life. Those most common 

 agreed with what Wilson in 'Chapters on Evolution' called " Cloe 

 bioculuta," except that, in the figure given on page 266, the tail-hairs 

 are shown all three-feathered on both sides : my Turkish larvae had 

 the middle hair feathered on both sides, but the other two only on 

 the inside ; the figure of Cloiion dipterum, given on page 432, vol. v. 

 of ' Cambridge Natural History,' is exactly like the Turkish forms. 

 I frequently had the flies (both male and female) emerge from my 

 aquaria, so I knew them well by sight as Cloe bioculata. I find by 

 my note-book that it was on September 27th, 1901, I caught a 

 female May-fly {Cloe bioculata) on the glass of my window, by taking 

 hold of her wings. She at once flicked her body round, and 

 deposited a fairly large mass of something on my finger. Thinking 

 it might be her eggs, I put a drop of water on it, and examined it 

 with a pocket lens. To my great surprise I found it was a "squirm- 

 ing mass " of living young ones. I washed them off into a small 

 aquarium, where they found plenty of food, as an hour later when 

 I placed some in a small tank for examination under the microscope, 

 I could see they had been eating freely. They had only ttvo tail- 

 hairs, no "gills," five dark spots on the head, two on each side near 

 the top of the head, and one lower down in the centre of the head 

 nearly over the mouth : this looked as if much deeper in the tissue 

 of the head, the others seemed to be on the skin. The next day 

 (28th), I caught another female, she did the same thing, but in this 

 case only a small number were larvte, the bulk of the mass being 

 eggs; still, on putting some under the microscope, I could see they 

 were on the point of hatching, and some did hatch while I had them 

 under observation. I placed these in the same aquarium with the 

 others. After about a week, in which no changes worth taking 

 note of took place, pressure of business and absence from home 

 prevented my making more observations until November 7th, when 

 on examination of the aquarium I found plenty of the May-flies alive, 

 and grown considerably. They had three tail-hairs and gills. I 

 found a number of cast skins, and have reason to think that at least 

 three moults had taken place since the centre tail-hair had developed, 

 as I found skins with this hair of various lengths. Evidently, 

 having come into the room, these flies were unable to find their w^ay 



ENTOM. — AUGUST, 1910. S 



