CECIDOMYID^E. 



379 



cecidomyian larvae, with the division between the segments in- 

 dicated by rows of minute spines. From the germ-balls (a, 

 nearest the posterior end of the body) the embryo is gradually 

 formed (as at a in the eighth and ninth rings of the body), 

 when they assume a cylindrical form like the eggs of the adult 

 fly of this family. These eggs may be compared with the 



Fig. 294. Fig. -2!:5. Fig. 296. 



"pseudova" of the Aphis, and are developed from the two 

 large fatty bodies (corpora adiposa) which are situated one on 

 each side of the body. These "false eggs" increase in num- 

 ber and develop until the entire cavity of the mother larva be- 

 comes distended with young worms like itself, and which are 

 finally born and may be compared with the wingless broods of 

 Plant-lice.* 



* Grimm thinks that the term "pseudova" is objectionable, as in the paedo- 

 genetic Chironomus the winter ova, as well as the summer, or false ova, develop 

 without previous fertilization by the male. 



