660 FAMILY: TRICHOMONADID.E 



Miura (1894), and Fonseca (1916), and is not uncommon in the centrifuged 

 deposit from urine. It is possibly the same species as T. vaginalis. 



T. vaginalis appears to be of common occurrence in cases of vaginitis, 

 where the exudate is acid in reaction. Thus, Hausmann (quoted by 

 Blochmann, 1884) found it present in 30 to 40 per cent, of females examined, 

 while Donne, its original discoverer, found it very common in France. 

 Brumpt (1913c) obtained 10 per cent, positive examinations in Paris, and 

 the writer has found it common in England. There appears to be little 

 reason to suppose that T. vaginalis is in any way a pathogenic organism. 



It seems quite possible that the three species of human Trichomonas 

 really belong to one species, and that the differences which occur are due 

 to variations in nutrition. The writer has studied the Trichomonas of 

 the mouth, vagina, and intestine. Those of the mouth and intestine 

 resemble one another so closely that it is impossible to differentiate them, 

 and this is also true of the smaller forms which occur in the vagina. The 

 large vaginal flagellates are probably overgrowth forms. Ohira and 

 Noguchi (1917), as noted above, observed large forms of the oral Tricho- 

 monas in their cultures. In cultures made by the writer in Hogue's egg 

 medium the mouth and intestinal forms were identical, and though the 

 vaginal form was not maintained in subculture in this medium, those 

 flagellates which remained active for some days were indistinguishable from 

 the cultural flagellates of the mouth and intestine. Lynch (1922), who 

 has cultivated all these forms, states that under the same conditions they 

 are identical, and that there is no means of differentiating them. Should 

 this prove to be the case, the name T. vaginalis will have priority over all 

 others. 



TRICHOMONAS IN ANIMALS. 



Species of Trichohionas are very common parasites of the intestinal 

 canals of animals. The csecums and large intestines of guinea-pigs and 

 rats, for instance, are often swarming with these flagellates, which, on 

 account of their large size, are more easily studied than the human forms. 

 They are common in birds, reptiles, and amphibia, and also occur in 

 invertebrates. Many of these have been given distinctive names, but 

 whether each host has its own species cannot be stated at present. The 

 various species described are very uniform in character, and differ from 

 one another chiefly in size. T. muris of the mouse varies in length from 

 3 to 20 microns at least, so that dimensions are of little value as specific 

 characters unless they can be proved to be constant. 



Trichomonas muris (Grassi, 1879). — This common flagellate of the intes- 

 tine of rats and mice, and possibly other rodents, was first noted by Grassi 

 (1879a), who named it Monocercomonas muris. Later (1881a) he referred 



