STUDIES ON CEYLON H^MATOZOA. 



753 



mentaiy tract. The cells lining the intestine are very large 

 and richly ciliated ; their protoplasm has a strong affinity 

 for all nuclear stains, including the red element in Twort's 

 stain. The nuclei are very large and reticulate, often showing- 

 several karyosomes. 



The stages of the parasite in the leecli had to be studied 

 for the most part upon section material; sublimate acetic and 

 Fleraming's fluid were the fixatives used. The leeches were 

 usually placed between two slides, so as to prevent undue 



Diagram of the alimentary tract of O z o b r a n c li u s s li i p 1 e y i . 



retraction. As regards staining, Delafield's hfematoxylin, 

 Twort's stain, thionin, methyl-blue eosin, and Mayer's htema- 

 lum were all used with good effect, lisemalum and Delafield 

 being the most generally useful. Heidenhain's iron-liEema- 

 toxylin was quite impossible, as it darkened the whole 

 intestinal region so intensely that, long before that region 

 was sufficiently colonrised, the remainder of the section was 

 completely bleached. 



I am indebted to Mr. Peter Jamieson for the skill with 

 whicli he has cut the many sections required. 



I may mention in passing that the intestine of the leech is, 



