389 



G '-^ H 



Text figs. A-F. Diagram of the Giant Tracheoloblast in trans- 

 verse section, showing successive stages in the formation of 

 tracheoles. 



Text fig. G. Developing spiracle of propodeum from the larva 

 shortly before pupation. Note the great "clip," through which 

 passes the lumen of the air tube (st.). Closing of the clip is 

 brought about by relaxation of the muscles (mcl.). 



Text fig. H. Diagram of respiratory system of adult Avasp : sp., 

 spiracle; d.l.a.s., dorso-lateral air sac; v.l.a.s., ventro-lateral air 

 sac. 



