272 



ELEMENTARY STUDIES IN INSECT LIFE 



and pass it into tlic stomach proper. Lying alongside 

 this stomach, and connected with it, can be seen on 

 each side three long tubes. These are glands (pouches 

 or ceca), and secrete a fluid which enters the stomach. 

 It passes forward into the crop, and acts upon the 

 food there also. From the proximity to the stomach, 

 these pouches are frequently called gastric ceca. Pla- 

 t <';i u and other writers equally authentic, claim that 

 the digestive properties of the fluid secreted in them 

 agree with the pancreatic juice of vertebrates. 



The food, after leaving the stomach, passes into the 

 intestines, the upper part of which is called the ilenm, 

 the middle part the colon, the terminal part the rectum. 

 At the forward end of the ileum can be seen a large 

 number of tubes (malpighian tubes) running backward. 

 These are believed to perform the functions similar t<> 

 that performed by the kidneys in the higher animals. 

 While the food is in the stomach, and as it passes 

 through the ileum and the colon, the nutritive portions 

 oozing through the walls of this digestive tube enter the 

 circulation. The waste material is carried off through 

 the rectum. 



Make a drawing of the dorsal view of the alimentary 

 canal, and name the parts. 



NERVOUS SYSTEM. 



Cut the caudal extremity of the alimentary canal ; 

 pin this far enough to the side to allow free view of 

 the whole tract immediately beneath. Here can be seen 

 the nervous system. It consists of a series of ganglia, 

 or masses of nervous matter, situated under the di- 

 gestive canal. These ganglia are arranged along the 

 body just next to the digestive tract. They are placed 



