OF THE ALIMENTARY TRACT 



159 



the infection, according to Kofoid (1929). Heg- 

 ner and Ratcliffe (1927) found 22 of 23 dogs harbored 

 a similar organism. 



The form of Trichomonas elongata is the character- 

 istic pear shape, being broader and more blunt 

 anteriorly and tapering posteriorly. It is usually 

 from 10 to 18 microns long by about 5 to 8 in width, 



Fig. 24. — Trichomonas elongata. 



Drawings of specimens from culture, stained by iron-haema- 

 toxvlon. X 1800. 



but much larger forms may be seen, especially in 

 culture. 



Its activity depends upon the material and en- 

 vironment of its growth. In heavy debris with little 

 fluid it may crawl about, twisting and turning, 

 elongating and shortening at will as it passes through 

 the avenues of its course. Its body is flexible and 

 plastic. In liquid medium as in fresh culture, or 



