134 



MORPHOLOGY AJSD CULTtJtRE OF MICROORGANISMS 



suckeir, by which it attaches itself to the intestinal epithelium of the 

 animal in which it lives. It is said to cause diarrhoea in man, and 

 also a fatal disease of the intestines in rabbits; but it is almost invari- 

 ably found in the duodenum and first portion of the small intestine of 

 normal laboratory animals such as mice, rats, and rabbits. 



yH/K 



Fig. 97. — Lamblia intestinalis. A, Ventral view; N., one of the two nuclei; ax., 

 z.xostyle&; fl.'-, fl.^, fl.',Ji.\ the four pairs of flagella; s., sucker-like depressed area on 

 the ventral surface; «., bodies of unknown function. , {After Wenyon (277) from 

 Minchin.) ' 



The SPOEOZOA are parasitic protozoa which multiply by the produc- 

 tion of spores at some stage of their life cycle. There are very many 

 sporozoa and so, for convenience of classification, they are subdivided 

 into seven orders. The Gregarina have a very distinctive shape; the 

 single cell, of which they are composed, is divided into two or more 

 divisions. The first of these divisions is furnished with hooks ^ or other 

 structures through which the parasite attaches itself to its host. None of 

 the gregarines are parasitic on mammals; worms are the hosts for some 

 of them. The Coccidia are usually parasitic within certain cells of their 



