AMORPHA POPULI. 475 



to detect, but appears a little paler than the surrounding surface 

 of the egg [Received July 21st, 1897, from Mrs. McMillan, 

 described same day under a § lens]. The eggs are very large, 

 nearly globular, some are rather more oval ; smooth-shelled, of 

 a very delicate greenish tint, and glistening like so many pearls. 

 A few days before they hatched there could be seen through the 

 shell what looked like two air-bubbles, and a few hours before 

 hatching the form of the embryo larva could just be discerned 

 of the same colour as the shell, though the latter when the 

 larva has left it is quite clear like glass (Buckler). Of broad 

 oval outline, nearly as deep as wide, the shell glossy, but when 

 magnified is seen to be covered with a very fine reticulation, 

 irregularly varying from hexagonal to almost square meshes, in 

 colour pale yellowish-green. Some eggs I have measured were 

 over 2mm. long and 175mm. wide, but the largest of both layings 

 (1882 and 1886), those in each case that were laid on the first day, 

 were i^mm. long and r6mm. wide; those of the second, third, fourth, 

 and fifth days i'8mm. long and i'6mm. wide; those of the sixth 

 and eighth days slightly smaller ; those of the ninth and tenth days 

 1 -65mm. long and i'45mm. wide, and the last egg I found in the 1882 

 laying was only i'6mm. by i^mm. (Hellins). Kowalewsky has used 

 (Mem. Ac. Sci. St. Petersb., (7), xvi., pi. xii) the eggs of this species for 

 some of his embryological investigations (see also a?itea, vol. i., p. 22). 

 Parthenogenesis has been reported in the species by Meisner (p. 45 (18 18)). 

 Habits of larva. — The newly-hatched larva sometimes eats 

 the greater part of the eggshell as soon as it is hatched, others, 

 however, eat only enough to enable them to escape from the shell. 

 Even before the first moult they eat pieces of the entire substance 

 of the willow or poplar leaves on which they are feeding (Buckler). 

 The larva of this species has only three moults, whilst those of 

 the other two British Amorphid species have four. Whether this 

 is always the case I cannot say. Chapman states that some larvae 

 of Moma alpium (orion) have four moults, others five, and that this is 

 not a sexual difference, as is the extra moult in the female larva of 

 Notolophns antiqua. The young larvae have very similar habits 

 to those of S. ocellata, but, as they get older, the position in which 

 they rest is very different; this is nearly always with the head 

 downwards, and although the forepart of the body is raised, as 

 in S. ocellata, the head is curved inwards towards the leaf or twig ; 

 they will grasp the stalk of a leaf with their anal claspers only 

 and hang down behind it, and it is quite remarkable how small a 

 sallow leaf suffices to hide a fullfed larva. On poplars I have 

 frequently noticed them, when they have eaten half the leaf, so 

 resting as to represent the eaten portion themselves, and they are 

 then so well protected that, with any wind, it would, I think, be 

 impossible to detect them. I have noticed that the larvae are 

 much easier to find on misty mornings and before the sun is up. 

 Probably the explanation of this is that, in bright sunshine, the 

 light and shadow are much stronger, and consequently the slight 

 difference in tint between the larva and the leaf is not so noticeable. 

 The same fact holds good with S. ocellata, and I think that, as 

 a rule, the protective coloration of larvae is most perfect in sunlight 

 or in full daylight (Bacot). Borkhausen notes (Sys. Besch., ii., p. 



