ON THE ORIGIN AND 



[CHAP. 



cellular mass forms a new skin beneath the original 

 cuticle, distinctly divided into segments, and provided 

 with certain appendages. After a while the old 

 cuticle is thrown off, and the larva gradually assumes 

 the form shown in Fig. 29. The subsequent meta- 

 morphoses of Polynema offer no special peculiarities. 



From these facts and, if necessary, many more of 

 the same nature might have been brought forward 

 it seems to me evident that while the form of any 



FIG. 28, Embryo of Polynema (after Ganin). 29, Larva of Polynema 

 asc h, rudiments of the antennae ;flsck, rudiments of the wings; bsck, 

 rudiments of the legs ; vfg, lateral projections ; gsch, rudiments of 

 the ovipositor;_/, fatty tissue. 



given larva depends to a certain extent on the group 

 of insects to which it belongs, it is also greatly 

 influenced by the external conditions to which it is 

 subjected ; that it is a function of the life which the 

 larva leads and of the group to which it belongs. 



The larvae of insects are generally regarded as being 

 nothing more than immature states as stages in the 



