656 FAMILY: TRICHOMONADID^ 



considerable expenditure of time and labour. It should be clearly under- 

 stood that before a Trichomonas is reported as having a particular number 

 of flagella, it is necessary to observe this number in the majority of the 

 forms present. Some dividing forms will have a larger number of fiagella, 

 while in others it will be impossible to detect the full number. Neverthe- 

 less, by careful observation it is not difficult in the case of pure infections 

 to determine the normal flagellum number for the form present. The 

 writer has seen the form with four flagella on many occasions, that with 

 five only a few times, but the one with three only once. 



Derrieu and Raynaud (1914) proposed the name Hexamastix ardin 

 delteili for the human form with five flagella, while Chalmers and Pekkola 



(1916) mistook it for a Hexamita, which they named Octo7nitus hominis 

 (Fig. 289). Kofoid and Swezy (1924) employ the name Pentatrichomonas 

 ardin delteili for the one with five flagella. One of the five flagella is 

 described as a trailing flagellum longer than the others (Fig. 20). 



Trichomonas elongata Steinberg, 1862.- — Hoffle (1850) appears to have 

 been the first to observe Trichomonas in the mouth. Steinberg (1862) 

 studied these oral flagellates and named three distinct species: T. elongata, 

 T. caudata, and T.flagellata. It is evident that he was dealing with various 

 forms of one flagellate, so that if the oral Trichomonas be regarded as a 

 species distinct from that of the intestine, its proper name will be T. elon- 

 gata, the first of those proposed by Steinberg, and not T. buccalis, the name 

 suggested by Goodey and Wellings (1917). It is probable that Leeu- 

 wenhoek saw the flagellate in the tartar of his own and other people's 

 teeth, but there are no means of identifying it unless it is assumed that 

 Trichomonas is the only flagellate which can possibly occur in material 

 taken from the mouth. That other flagellates may occur in the mouth 

 has recently been demonstrated by Knowles and Das Gupta (1924), who 

 have found a species of Bodo in this situation. Mliller (1773) also noted 

 that flagellates developed in the course of four days in water to which 

 tartar from the teeth has been added. He named the organism Cercaria 

 tenax, but there is no conclusive evidence that he was actually dealing 

 with Trichomonas. It has been maintained by Goodey and Wellings 



(1917) that, in the oral form, the axoneme does not extend beyond the end 

 of the membrane as a flagellum, as it does in T. hominis (Fig. 269). The 

 writer has, however, found no difference in this respect between the 

 Trichomonas of the mouth and that of the intestine. The writer and 

 O'Connor (1917) noted that, in a case which constantly showed Tricho- 

 monas in the month, the flagellates never appeared in the diarrhoeic stools, 

 though they were specially looked for on many occasions. Lynch (1915o) 

 could find no Trichomonas \n the faeces of a woman who harboured Tricho- 

 monas, both in the mouth and vagina. The Trichomonas of the mouth 



