

Amnion and Serosa. Meanwhile, tin- blastoderm 



IK- uenn l;ind from either Bide, U -hown in I i 

 tin- t\v> fold> meet and Unite tO form two mem bran- Fig 194), nan 



an inner one, or <intnion. and an outer one, 01 



.a 



o o QQ o O 



FK.. 193. Transv :\ <>( 



mmin folds <.f Clytni. a, am- 

 Mili-rin; ;, inner layer 



rosa. Origin a!. 

 -.Mon's figures. 



I'M.. 194. Tr. 



onal membranes of Clytra. 

 a. ainnion; ac, amnion cavity; e, ectoderm; 

 /', inner layer (meso-entoderm) ; s, serosa. 

 After L^CAILLON. 



Segmentation and Appendages. On the germ hand, which repre- 

 sents the ventral purl of the future insect, the body segments are marked 

 }\\ l)v transverse grooves (Figs. 195, 197); this segmentation beginning 







-.:' 





c 



Fn;. 195. Germ band of a beetle, Lina, in three successive stages. A, unsegmented; 

 B, with oral segments demarkated; C, with three oral, three thoracic and two abdominai 

 segments. After GRABER. 



usually at the anterior end of the germ band and progressing backward. 

 Furthermore, an anterior infolding occurs (Fig. 196), forming the stomo- 

 dirum. from which the mouth, pharynx, oesophagus and other par 

 the fore gut are to arise; a similar but posterior imagination, or procto- 

 (Fig. U)(>). is the beginning, or fundament, of the hind gut. 



