THE EGGS OF CYCLOPIDES PALAEMON, ETC. 



16 



a non-circular outline in any section through the micropyle, and a 

 circular one in any section transverse to the micropylar axis. The 

 latter tendency has free scope, and almost invariably takes effect in 

 " upright " eggs. At first glance a Thymelicine egg looks like a flat 

 egg, having an oval outline, but we find that it has the micropyle on 

 top, and is, therefore (like those of all other butterflies), an upright egg. 

 Had the micropyle been at the end, it would have been a flat egg, and 

 we should have rejoiced at here finding how the more primitive flat 

 egg was to be found in the lowest family of butterflies. This is, 

 however, not so. Apart from the fact that lower, probably allied, 

 families [Castnia, Cossns) have " upright " eggs, the egg itself suggests 

 that it has been derived from an ordinary upright egg (with circular 

 outline), and is not at all directly derived from a flat egg. Most prob- 

 ably it is derived from an ordinary upright egg, in response to a 

 necessity of fitting more easily into folds of blades of grass, according 

 to the observation recorded by Hellins. 



What I wished to point out in the note referred to is, then, simply 

 this : That an egg may conceivably take any position, with micropyle 

 above, below, or laterally ; the micropyle is a fixed point, and cannot 

 be moved to another part of the egg, so that a flat egg with oval 

 outline, i.e., lying on its side, cannot continue to lie on its side, and 

 move the micropyle to the top. The oval outline of an egg with 

 micropyle on top has, therefore, no necessary relationship to one with 

 the micropyle at end. 



In order to get a little closer to the subject, I have made various 

 endeavours to get Adopaea flciva {linea) to lay some eggs, but in this I 

 have absolutely failed, in common with Mr. Hellins, although a refer- 

 ence to Hawes, in Tutt's Brit. Lep., viii., p. 108, distinctly suggests. 



Fig. 1. — P = EGG OF Cyclopides pal^mon : — 1, top view; 2, side 

 view. s = egg of c. silvids : — 1, top view; 2, side view. f = 

 eggs of Adop^a flava : — 1, 2, 3, top view of large and sjiall 

 eggs; 4, 5, side and end view of large egg; 6, 7, side and 

 end view of average (or perhaps slightly below average) eggs. 

 (All X 24.) 



however, that the former has done so. I have, therefore, l)een compelled 

 to obtain the eggs of A. /lava by dissection of females dying after 

 refusing to lay. This is not wholly satisfactory, but probably leads to 

 no important errors. 



