124 



INSECT TRANSFORMATIONS. 



n-reat deal of trouble, by alternately stretching' out and 

 contracting them, that it succeeds in rending this, and 

 sets itself at liberty*. Even then the young spider 

 can neither spin a web nor catch prey ; for it is still 

 enveloped in an extremely delicate membrane, which 

 it does not moult unless the weather is favourable 

 and fine f . 



Hatching of the egg of (he garden-spider {Epeira dtadema'). a, 

 natural size, b, egg magnitied, the cicatricula (a white spot) in the 

 front. C, the germ enlarged ; a, the head, and b, the body of the 

 embryo, d, the embryo spider ready to cast off its first skin. 



The latter circumstance will enable us to explain 

 some experiments made by Redi, who kept spiders 

 newly hatched for many months without food|. In 

 the experiments made by us upon the eggs of the wolf- 

 spider (JLycosa saccata), we more than once kept the 

 young in boxes, where they were forgotten and 

 without food ; and we uniformly found that they re- 

 mained lively and well so long as they did not cast 

 their embryo skin ; but when they did moult, they 

 could not long survive the want of sustenance §. 



In the eggs of moths, the embryo, previous to ex 

 elusion, may be seen through the shell, snugly coi ed 



* De Geer, Mem. vii. p. 196. i 



f Diet. Classique d'Hist. Nat. xii. 141. I 



X Redi, Esperienze, 99. ^ J. R. j 



