636 FAMILY: CRYPTOBIIDiE 



possible that a flagellate of tlie type of E. hotni?iis actually exists as a 

 human parasite, and further observations are necessary before it is finally 

 concluded that Tricercomonas is a synonym of Enteromonas. Lynch 

 (1922a), who has studied a case of infection with T. intestinalis in America, 

 has also cultivated from the intestine of the guinea-pig a flagellate having 

 the characters of Fonseca's E. Jiominis, so the possibility of such a form 

 occurring in man cannot be excluded. 



There is another aspect of the question, which has been referred to 

 above. In cases of infection with Chilomastix tnesnili it is not unusual to 

 find small rounded forms of this flagellate in which the cytostomal groove 

 is difficult to detect (Fig. 256, 7-8). These have essentially the structure 

 ascribed to E. hominis by the various observers who have recorded this 

 flagellate. Having examined the original films, the writer is in a position 

 to state that the flagellates described by Chalmers and Pekkola as 

 E. hominis from the Sudan are actually the small round forms of C. mesniJi. 

 It is possible, therefore, that Enteroynonas is a synonym of Chilomastix. 



Duboscq and Grasse (1924), from observations on the flagellates of 

 termites, arrive at the conclusion that both Enteromonas and Tricercomonas 

 are merely young forms of other flagellates. In the case of Enteromonas, 

 as pointed out above, there is considerable evidence in favour of this 

 view, but in the case of Tricercomonas of man there is no indication 

 whatever that it is a young form of any other flagellate. The form in the 

 termites which Duboscq and Grasse considered as of the Tricercomonas 

 type possessed both an axostyle and a parabasal (Fig. 279), in which 

 respects it differed from T. intestinalis from the human intestine. 



Boeck (1924), and Thomson, J. G. and Robertson (1925), report the 

 cultivation of T. intestinalis in Boeck's L.E.S. medium. 



8. Family: cryptobiid^ Poche, 1913. 



The flagellates which are included in this family are found in three 

 situations— viz., the blood of fish, the intestinal canal of fish and the 

 Chsetognathan Sagitta, and the vesicula seminalis and spermatophores of 

 molluscs and other invertebrates. Structurally, the flagellates from these 

 three situations are so similar to one another that many observers regard 

 them as belonging to a single genus. As will be explained below, the 

 correct name of the genus is Cryptobia Leidy, 1846, and strictly all the 

 forms should be included in this genus. The blood-inhabiting forms have 

 so long been known under the name Trypanojplasma, given them by 

 Laveran and Mesnil (1901c), that it seems better at present to retain them 

 as a distinct genus. 



The body of a typical member of the genus consists of an elongate 

 flattened portion of cytoplasm in which is a nucleus and a kinetoplast 



