GENUS: HEXAMITA 689 



Swezy (19216), wlio proposed establishing for it a new genus, Ditrichomastix, 

 and by Dobell and O'Connor (1921), who suggested that it was possibly a 

 dividing form of Tncercomonas intestinalis. Prom an examination of the 

 original film, the writer is able to state that the supposed Hexamita is a 

 Trichomonas. As is usual in a film, it is not possible to detect the complete 

 structure in every flagellate, but there is no doubt that the infection is one 

 of Trichotnonas, and no other flagellate (Fig. 289, 1-5). The majority of 

 forms in which the anterior flagella can be counted have four, a few have 

 five, while others have a smaller number. The protruding portion of the 

 axostyle in many is very long, while the basal fibre in some appears to be 

 continuous with the posterior flagellum. In no case were six anterior 

 flagella present, and it seems probable that some at least of the anterior 

 flagella depicted by Chalmers and Pekkola were merely fibres in the 

 medium. 



Other Species of Hexamita. 



According to Dobell (1909), the first observer to see a flagellate belong- 

 ing to this genus was Ehrenberg (1838), who named a form seen by him in 

 frogs, Bodo intestinalis. Dujardin (1841) named it Hexainita intestinalis 

 and described two other species which he saw in stagnant water, H. no- 

 dulosa and H. inflata. Biitschli (1878) united the two latter forms under 

 the name H. inflata, and called the parasitic one H. intestinalis. Grassi 

 (1879) referred to the form in the frog as Monomorphus ranarum. The 

 form described by Prowazek (1904rt) as Octomitus intestinalis from the 

 intestine of rats is certainly identical with H. ?nuris of the mouse, while 

 0. dujardini, described by Dobell (1909), from frogs and toads, is H. intes- 

 tinalis. Moroff (1903) described a species of Hexamita from the rainbow 

 trout. He regarded it as identical with the parasite of frogs and toads. 

 AlexeiefE (1910) observed a form in the fish, Motella tricirrata and M. mus- 

 tela, and (1911) another in species of Triton and axolotl. These were all 

 regarded as identical with H. intestinalis of the frog. H. parva is the 

 name given to a form seen by Alexeiefl (1912c) in the Ceylon tortoise, 

 Nicoria trijuga. The writer has seen this or a similar form in Testudo 

 radiata, T. calcarata, and T. argentina, and another in Python molurus. 

 Mackinnon (1912) saw a form in the intestine of tipulid larvae. Swezy 

 (1915), who has given the most detailed account of the structure and 

 division of these flagellates, described two new species {H. ovata and 

 H. batrachorum), both from the intestine of amphibia (Fig. 290). Escomel 

 (1925) gave the name H. brmnpti to a form found in the South American 

 batrachians, Telmatobius escomeli and T.gehshi. Belar (1916) described a 

 species {H . periplanetce) from the cockroach. Da Cunha and Muniz (1922), 

 H. avium from Brazilian birds, and Kotlan (1923), H. intestinalis from 

 the duck. Noller and Buttgereit (1923) recorded H. columbce from the 

 I. 44 



