134 



INSECT TRANSFORMATION 



the fore-gut. The stomach (Fig. 78 s) lined with digestive 

 cells uncovered by cuticle is a coiled tube somewhat broader 

 than the gullet ; it gives off four short, blind tubes at its front 

 end, immediately behind the crop. Behind the stomach 



ac.l 



II 



HI 



LSI 



long 



LsS 



Is 6 



FIG 77. FULL-GROWN LARVA OF OX WARBLE-FLY (Hypodermd 

 DIAGRAM OF TRACHEAL SYSTEM. X 5- 



/ ///, segments of thorax ; i 8, segments of abdomen ; a.s, anterior 

 spiracles ; /.s.i 6, lateral spiracles ; p.s., posterior spiracles ; long., 

 longitudinal tracheal trunks ; a.c., i 3, anterior connectives ; p.c., 

 posterior connective ; d.int.tr, dorsal internal tracheae ; dig. tr., tracheae 

 to digestive tube (numbers refer to the abdominal segments ; note the 

 sac-like swelling of dig. tr \) ; l.tr., outer lateral tracheae ; sp. tr., spiracular 

 tracheae (solidified). From Carpenter and Pollard, Proc. R. Irish Acad. 

 XXXIV. 



comes the narrower hind-gut or intestine (Fig. 78 int] derived 

 from the posterior ectodermal ingrowth and lined with chitin, 

 at its junction with the stomach come off paired Malpighian 



