6 4 



K. OGUMA : 



do with the hind intestine of the dragonfly, torn off from the more anterior 

 parts and evaginated through the anus. 



As is generally known, the hind intestine of the dragonfly consists of 

 the ileum and the rectum. In the adult, the ileum is much longer than 

 the rectum and has folded mucous epithelium. On the other hand, the 

 rectum has smooth epithelium, of which the distalmost part adjoining the 

 anus is distinguished from the remaining parts in being composed of smaller 

 cells and has been called the anal piece by some authors. The muscular 

 wall of the hind intestine is thickest in the anteriormost parts of the ileum ; 

 it is also thickened at the junction with the rectum where rectal tracheal 

 gills are attached. The hind intestine is invested in its entire length by 



Fig. I. Prolapsed hind intestine (HI) in situ. Enlarged. Fig. 2. Median sagittal section' 

 of the same. Fig. 3. Terminal part of the same. 



a, anal piece; c, chitin intima; dm, duct of Malpighian tubule; i, ileum; m, Malpighiaa 

 tubules; M, muscular layer; r, rectum; rg, rectal gill; t, trachea; tp, tunica propria. 



Malpighian tubules which open into the anterior end of ileum, making 

 their way through the thickened muscular wall of that part. 



Now, to obtain an insight into the structure of the pendant organ in. 



