THE COMMON COCKROACH 



135 



over it to the depth of an inch or so. Under these 

 circumstances, when the body is opened, the organs 



V 



FIG. 40. Digestive System of Cockroach, a^, oesophagus; a, 2 , crop ; b, giz- 

 zard ; c, hepatic caeca ; d, mesenteron ; e, Malpighian tubules ; /, ileum ; 

 g, colon ; h, rectum, 



within, being buoyed up by the surrounding liquid, are 

 displayed and rendered distinguishable to a much 

 greater extent than would be possible in the absence 



