38 INSECT TRANSFORMATIONS. 



goose-quill in the eggs of the drinker and other moths 

 which we have dissected;* but in the eggs which are 

 deposited in moist places, and in those of spiders, it is 

 extremely thin.y The eggs of saw-flies, ants, &c, 

 which grow larger, as we shall afterwards show, du- 

 ring the process of hatching, must possess an expansi- 

 ble shell to allow of their enlargement. The yolk and 

 white in the eggs of birds are separated from each 

 other by a very fine membranous bag in which each 

 is contained ; but in the eggs of insects, what an- 

 swers to the yolk consists of distinct minute globules, 

 which float in the white, if we may call it so, for it does 

 not, as we have ascertained, coagulate in boiling water. 

 The eggs of the gypsey moth iHypogijmna dispar), 

 which we boiled, still continued partly fluid, though 

 the brown matter answering to the yolk was consider- 

 ably thickened. The portion which does not thicken 

 by boiling most probably forms the first internal fluids 

 of the caterpillar, answering to the blood of quadru- 

 peds. The point where the caterpillar originates, 

 — answering to the scar {Cicatricula) in the eggs of 

 birds, — we can readily distinguish even by the naked 

 eye in the larger species of eggs, as it lies always 

 immediately under the shell.*' ' Having directed,' 

 says the younger Huber, ' my close attention to the 

 eggs of ants, I remarked that they were of diflerent 

 sizes, shades, and forms. The smallest were white, 

 opaque, and cylindrical ; the largest, transparent, 

 and slightly arched at both ends ; while those of 

 a middle size were semi-transparent. On holding 

 them up to the light I observed a sort of white ob- 

 long cloud; in some, a transparent point might be 

 remarked at the superior extremity ; in others, a 

 clear zone above and underneath the little cloud. The 

 largest presented a single opaque and whitish point 



* J. R. t Kirby and Spence, Intr. 86. 



