REPORT OF THE STATE ENTOMOLOGIST I91O 9/ 



he large, white mother larvae, by a great increase in the ecto- 

 ierm, accompanied by its folding and extension anteriorly around 

 :he posterior extremity, the development of the large lobes an- 

 :eriorly and its segregation into somatic masses, indistinctly shown 

 >n plate 2^, figure 2, and apparently producing a peculiar cuboidal 

 ispect illustrated on plate 28. The greatly developed mesoderm in- 

 ludes a series of large, cuboidal cells, some at least probably being 

 :he polar cells, and a certain portion destined to develop into a 

 nuch more conspicuous mass to be described later. These changes 

 ire accompanied by a shrinking of the embryo from the extremi- 

 ies of the amniotic sac and the development of the digestive sys- 

 em by an invagination from both extremities. This latter is in- 

 licated in living embryos of young yellowish larvae, by the forma- 

 ;ion of irregular lobes at each extremity and the appearance in 

 ;he region of the sixth to the twelfth segments, of a considerable 

 nass of large-celled tissue, occupying most of that portion of the 

 Dody cavity and which we believe to be mesoderm (pi. 35, fig. 2) 

 md identical with that mentioned above. The changes from now 

 Dn are rapid. This conspicuous mass of mesoderm gradually be- 

 :omes absorbed or reorganized into organs such as the digestive 

 system, its appendages and especially the ovaries, while the de- 

 ireloping adipose tissue expands, occupies more space and pro- 

 luces a three-rowed appearance in the embryo (pi. 35, fig. 3). 

 Development of the head now proceeds, the mouth parts become 

 nore definite, the ocular spot visible and the lobes at the posterior 

 extremity become well defined. Motion may be observed in the 

 embryo and shortly it is ready to escape from the mother larva, 

 rhe length of the fully developed embryo is about i mm. It is 

 frequently nearly as long as the small, yellow mother larva and 

 ipproximately half as long as the large, white larva. 



The development of the embryo reacts upon the mother larva 

 md she soon assumes a rather characteristic quiescent form, un- 

 doubtedly an outcome of her lowered vitality due to the rapid ab- 

 sorption of nourishment by the young. This results in the relax- 

 ng of the muscles, especially the transverse girdling bands at the 

 margins of the segments. The change in the condition of the 

 nother is probably explainable solely upon physiological grounds, 

 rhe time elapsing between the assumption of the quiescent stage 

 by the mother larva and the escape of the young is about seven 

 iays. The first part of this period the embryos rarely exhibit signs 

 3f life, though distinct motions of the head and anterior segments 



