A TYPE OF EMBRYONIC DEVELOPMENT IN INSECTS 



17 



Meanwhile the yolk has receded along the medial line, establishing a 

 connection between the lateral sinuses, thus forming the single definitive 



amf 



mge.p 



Fig. 19. — Parasagittal section of embryo, (am) Amnion, (amf) Amniotic fold, (br) 

 Brain, (ch) Chorion, {ect) Ectoderm, (eps) Epineural sinus. (/) Fat. (mes) Meso- 

 derm, imge) Anterior (a), posterior (p), mid-gut epithelial rudiments, (nc) Nerve cord. 

 {neurp) Neuropile. {proct) Proctodaeum. (r) Mid-gut epithelial ribbons, (ser) Serosa. 

 {splm) Splanchnic mesoderm, (stom) Stomodaeum. 



epineural sinus (Fig. 18, eps). The cells of the middle strand are then 

 liberated into the epineural sinus, some perhaps to share later in the 



