156 RESEARCH IN PROTOZOOLOGY 



it seemed reasonable to conclude that in all probability Trichom- 

 onas infection in man might also be acquired from a variety of 

 sources, and it seems likely that any animal which harbors the 

 second general type of Trichomonas discussed above, in other 

 words, any of the three types found in man, may serve as a 

 reservoir host for human Trichomonas infections. 



Hegner (19286/) was able to establish flagellate infections in 

 young negative chicks. Among these were trichomonads from seven 

 different species of hosts. After securing these positive results, 

 Hegner (1928^^) states, ''There seems to be no doubt but that 

 fowls are capable of transmitting certain human intestinal pro- 

 tozoa," and further suggests that several of the trichomonads 

 established experimentally in fowls from different mammals "be- 

 long to a single species and not to separate species as regarded by 

 many at the present time." He thus appears to have altered his 

 earlier opinions regarding the rigidity of host-parasite relations, 

 at least in so far as Trichomonas is concerned. 



PROBLEMS AND METHODS 



In addition to the trichomonads mentioned above, others have 

 been reported from the armadillo by Fonseca (1915), by Braune 

 (1913) from cattle, by Fantham (1920) from the horse, sheep 

 and cattle. Trichomonads have also been found in birds, rep- 

 tiles, amphibia, fish, leeches, mollusca and insects (see Wenyon, 

 1926). 



Additional findings will undoubtedly occur and in studying the 

 host-parasite relationships of this group, many more transmission 

 experiments should be attempted. It would be expected that trans- 

 mission will be easiest in the groups most closely related, although 

 Hegner's results with fowls indicate a very wide range of trans- 

 mission with this parasite, since he has already accomplished trans- 

 mission between hosts belonging to two different classes of ver- 

 tebrates. 



The experimental method is the only method to employ in ascer- 

 taining these facts, and the experiments must be done with care- 

 fully selected negative animals. The best method to employ in 

 selecting animals negative for Trichomonas is to culture freshly 

 passed feces, collected by enema or following a purge, in the Locke- 

 egg-serum medium, and examine for Trichomonas. This flagellate 

 grows the most readily in zntro of any of the intestinal protozoa, 



