30 



intestinal division of the straight intestine. Their maxi- 

 mum length is about 0*2 mm. They are finely granular, 

 with the nucleus at any level from near the free extremity 

 to near the bottom of the cell. They bear a covering of 

 very short cilia. Sometimes, at the middle of the free 

 surface, there is a little groove in which the cilia are 

 matted together. This is not constantly present, and it 

 is probably due to the action of reagents. 



The epithelium, of the intestinal portion especially, rests 

 on a layer of dense connective tissue, which fills up the 

 spaces between the epithelia forming the anterior and 

 posterior folds, and is found in patches all round the 

 intestine. This presents no very obvious structure. It 

 seems to be largely fibrous, with nuclei scattered through 

 it. It stains densely with haematoxylin. It includes 

 large irregular spaces, evidently blood channels ; in its 

 substance are seen corpuscles of various kinds, blood 

 corpuscles and corpuscles containing a greenish substance. 



The crystalline style (St, fig. 12, PL III.) completely 

 fills the lumen of the left division of the straight portion 

 of the gut. In sections made from hardened specimens, 

 the style is usually seen to be retracted away from the 

 wall of the sheath. But since, in such preparations, it 

 may be observed that the superficial layer of the ciliated 

 epithelium is in some parts torn away and adherent to the 

 substance of the style, it is evident that this contracted 

 condition is due to the process of embedding ; and the 

 same cause most probably gives rise to cavities sometimes 

 observed in its marginal part. In hand sections of the 

 animal, simply killed with formol and examined under a 

 low magnification, the style appears perfectly homogen- 

 eous, and completely fills the sac. 



No obvious structure is to be observed in the style 

 except a very delicate concentric lamination. It is per- 



