672 FAMILY: TEICHOMONADID^ 



have generally been known by the generic name Trichomastix, but owing 

 to the fact that Vollenhoevan had previously proposed this name for an 

 insect, Kofoid and Swezy (1915«) introduced the name Eutrichomastix. 

 It seems probable that, in some cases at least, the Eutrichotnastix forms are 

 merely Trichomonas in which the posterior flagellum has become free. 

 Chatton (1920), as noted above, found that in cultures the TricJiomonas 

 of the guinea-pig might assume either form. Eeichenow (1918, 19206) 

 noted that occasionally in lizards (Lacerta muralis and L. viridis) the blood- 

 stream was invaded by Eutrichoinastix from the intestine. In one case in 

 which a lizard had died of such an infection, at the time of death the only 

 forms present in the blood were of the Eutrichomastix type. On the next 

 day, however, in addition to these there were other flagellates of the 

 Trichomonas type present. Reichenow considers it possible that the 

 latter had been derived from the former, and that the two types may be 

 stages of one organism. In favour of this view is the well-known fact 

 that where flagellates of the Trichomonas type occur, very frequently 

 others of the Eutrichomastix form are present at the same time. Thus, 

 Dobell (1909) noted that T. batrachorum was often associated in the 

 frog's intestine with E. batrachorum, and a similar association was noted 

 by Prowazek (1904rt) in the case of lizards, and by Martin and Robertson 

 (1911) in fowls. On the other hand, it appears that sometimes the 

 flagellates are found in the Eutrichomastix form when Trichomonas is 

 absent, as in the case of E. serpentis seen in a snake by Dobell (1907a). 

 The writer has cultivated a Trichomonas of the tortoise {Testudo radiata), 

 the python {Python molurus), and the frog, and in these cases there was no 

 tendency for the flagellates to assume the Eutricho^nastix form. For the 

 present, therefore, it seems best to regard the flagellates as belonging to 

 distinct genera. 



The flagellates of the genus Eutrichomastix have the same structure as 

 those of the genus Trichomonas, except that all the flagella, which are 

 four in number, are free, there being no undulating membrane. One of 

 the four flagella usually functions as a trailing flagellum. 



It is unnecessary to give a detailed description of these flagellates, 

 which in their life-history and structure correspond very closely with the 

 various species of Trichomonas. 



Haughwout and Horrilleno (1920) state that they saw a flagellate of 

 the Eutrichomastix type in a human stool in Manila. They refer to it as 

 Eutrichomastix sp. As only a single flagellate was seen, it is possible that 

 they were dealing with an altered Trichomonas. 



E. lacertce was described by Prowazek from the intestine of species of 

 Lacerta. What is probably the same form occurs also in other lizards, 

 as noted by the writer (1921) in the case of L. agilis and Agatna stellio. 



