37 



named in honor of Malpighi, one of the early anatomists. 

 As uric acid is found in the Malpighian vessels, they are 

 supposed to correspond to the kidneys in function. 



Determine the number of Malpighian vessels. 



Intestine. The part of the alimentary canal extending from 

 the ventriculus to the caudal end of the body is the intes- 

 tine ; the part immediately caudad of the ventriculus is the 

 small intestine ; following the small intestine is the large 

 intestine ; there are two bends in the cephalic part of the 

 large intestine ; the first extends dorsad and cephalad ; the 

 second, dorsad and caudad ; the rectum is not a well-defined 

 part of the intestine in this insect. 



Attachments of the alimentary canal. The alimentary canal is 

 attached to the body-wall and thus held in place in various ways. The 

 most obvious attachments are those of the ends of this organ. In addition 

 to these direct connections, the alimentary canal is indirectly connected to 

 the body-wall as follows: 



By trachecE. From the lateral wall of each abdominal segment, large 

 tracheae arise ; many of the minute branches of some of these extend to the 

 walls of the alimentary canal and thus tend to hold it in place. 



In connection with the tracheae, the action of the masses of adipose tissue 

 should be observed. These large masses, which to a great extent are held 

 in place by the tracheae that extend to the alimentary canal, serve as cushions 

 which tend to keep the organ in place. 



By muscles. A large number of very delicate muscles extend from the 

 ventral wall of the head to the oesophagus. In the specimen which the stu- 

 dent is now studying, only the ends of these muscles which are attached to 

 the oesophagus can be observed, as the attachments of these muscles to the 

 wall of the head were cut away in the preparation of the specimen. Large 

 muscles extend caudo-ventrad to the intestine from the line on the dorsal wall 

 of the body between the eighth and ninth abdominal segments. From 

 within the anal prolegs, muscles extend cephalad into the ninth abdominal 

 segment and are attached to the intestine. Other muscles are described in 

 the next section. 



By the suspensoria of the viscera. There are several, long, fine threads 

 that are so attached as to tend to hold the alimentary canal and other viscera 

 in place. These may be termed collectively the suspensoria of the viscera. 



