54 Elementary Zoology. 



and tissues can receive their supply of oxygen and get rid of 

 their carbonic acid. 



A considerable portion of the space within the body is 

 taken up by the fat body. This is an irregular ramifying mass 



sp 



INT 



KiG. 27. — Tracheal system of Cockroach. 

 (After Miall and Denny.) 



sr, spiracles ; ST, stomach ; int, intestine. 



Fig. 28.— Tracheal system of Cocltroach 

 after removal of alimentary tract. 

 (After Miall and Denny.) 



of white tissue made up of cells in which fat globules are 

 deposited. It has also been found to contain uric acid, and 

 therefore it seems to play some part in excretion 



