SALIVARY 

 GLANDS 



ABDOMINAL 

 GANGLIA 



6TIGMATA*', 



Fig. 202. Structure of Cockroach (Periplaneta orientalis] (enlarged) 



A, Digestive organs and nervous system. B, Air-tubes (tracheae), c, Heart and muscles, i-in, Segments of 



thorax; i-io, segments of abdomen. 



347 



