ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



361 



elongates and is constricted. Multiple fission also occurs. It may be 

 preceded by the formation of giant individuals, in which the nucleus may 

 divide several times, eight sometimes occurring. A " linear plasmodial 

 phase " of this sort separates by plasmotomy into its constituent zooids. 

 The parasite feeds by osmosis ; there is no mouth. The spiral course of 



A - x.\ '^^T^^^^^k ''/' 



Parasites in villi of intestine attached to mucous lining, x 3000. 



myonemes is effective for an energetic thrust against or into the cells of 

 the host. The long nucleus is advantageous for nucleo-cytoplasrnic 

 exchanges in the absence of marked cyclosis. The new type, which 

 requires a new family, links Polymastigina and Trichonymphidffi, but 

 without close relations in either group. . J. A. T. 



