670 FAMILY: TRICHOMONADID^ 



discovered a Trichofnonas in the blood of a pigeon. He claimed to have 

 inoculated it to rabbits and guinea-pigs. Martoglio (1917) discovered a 

 similar form which had four free flagella in the blood of fowls in Eritrea, 

 and proposed to place it in a new genus as Hcemotrichomonas gallinarum. 

 He also places in this genus as H. ophidium the Trichomonas discovered 

 by Plimmer (1912a) in the blood of snakes which had died in the Zoological 

 Gardens. Lanfranchi (1917) again refers to the form previously described 

 by him, and places it in Martoglio's genus as H. colmnbcB. These forms, 

 which occur in the blood, are almost certainly the result of invasion of the 

 vessels by intestinal flagellates, so that there is no justification for the 

 genus Hcemotrichomonas, as indeed Sangiorgi (1922), who saw a Tricho- 

 monas in the heart blood of a dead mouse, has pointed out. For some 

 reason which is not quite clear he believes that the flagellates seen by 

 Lanfranchi and Martoglio in the blood of the fowd and pigeon were not 

 Tricho?nonas, but Toxoplasma. As pointed out by Plimmer (1912), the 

 intestinal Trichomonas of amphibia are liable to invade the blood-stream 

 shortly before death. As noted above, the writer (1920) has seen T. hominis 

 in the tissues of the intestinal mucosa of human beings (Fig. 267). 



Genus: Gigantomonas Dogiel, 1916. 



This genus was established by Dogiel (1916) for a flagellate of the 

 intestine of the termite, Hodotermes mossambicus. The chief characters 

 are the size and the fact that one of the anterior flagella is thicker and 

 longer than the others. 



Gigantomonas herculea Dogiel, 1916. — This is the only representative 

 of the genus. It measures from 60 to 75 microns in length and 30 to 35 

 microns in breadth. In structure it resembles a Trichomonas. It seems 

 possible that the flagellate represents an overgrown form of T. macrostoma , 

 which Dogiel found in the same host. 



Genus: Ditrichomonas Cutler, 1919. 

 This is a genus which was founded by Cutler (1919) to include a flagel- 

 late of termites which has essentially the same structure as Trichomonas 

 (Fig. 276). The single species, D. termitis, possesses only two anterior 

 flagella. It has two blepharoplasts, a nucleus, axostyle, and a basal fibre 

 running along the line of attachment of the undulating membrane, to 

 which the backwardly directed flagellum is attached. One of the ble- 

 pharoplasts, which Cutler terms the membrane granule, gives rise to the 

 basal fibre and the axoneme of the posterior flagellum. The other gives 

 origin to the axonemes of the two anterior flagella and the axostyle, as 

 well as a rod-shaped body called the parabasal. The latter structure may 

 be half the length of the body, and appears to be homologous with the 



