Fic. 21.—Posterior cross-section. h., heart; c., gastric cecum; m., Mal- 
pighian tubule; t., trachea; f., fat bodies; d., intestinal diverticulum. 
Fic. 22—Longitudinal section of Malpighian tubule, to show the 
similarity of cell elements. 
Fic. 23.—Cross-section of wall of diverticulum. m., muscle wall; 
c., cell layer. 
Fic. 24.—Cross-section of cell of diverticulum. 
