THE STICK INSECT. 85 
and pin the sides back. Cover with water. Cut the 
intestine and turn it and the stomach forward, 
cutting the tracheze when necessary, and tearing as 
little as possible. Turn the reproductive organs 
backward in the same way. The dorsal vessel will 
be seen as a fine tube lying along the middle line. 
Norrt.—The pulsations of the dorsal vessel can be easily seen through 
the integument in living specimens of the leaf-rolling caterpillars belong- 
ing to the family Tortricidae. 
