54 



THE ANIMAL PARASITES OF MAN 



Trichomonas intestinalis, R. Leuckart, 1879= Trichomonas 

 hominis, Davaine, 1854. 



Some authors believe that a second trichomonad inhabiting man, 

 Trichomonas intestinalis, R. Lkt, is identical with Trichomonas vaginalis, 

 Donne. Leuckart's species was based on the discoveries of Marchand 

 (1875) and Zunker (1878), who stated that according to all appearances, 

 and in their opinion, it was the same as Cercomonas iniestinalis, Lambl, 



1875 (nee 1859), which they found in 

 the faeces of patients suffering from 

 intestinal disorders. The organism 

 is described by them as being pear- 

 shaped and 10 jj, to 15 //. in length 

 and 3 ^ to 4" /x in breadth. The 

 posterior extremity terminated in a 

 point (fig. 17). 



(After Grass!.) 



A row of twelve or more cilia was said to 

 commence at the anterior end and extend 



FIG. 17. Trichomonas intestinalis, Lkt. O ver the body. Leuckart stated that this 



parasite, placed by the two authors in the 

 genus Cercomonas, was a Trichomonas, and 

 that they mistook the undulating membrane for cilia, and overlooked the flagella. 

 Notwithstanding its striking similarity with T. vaginalis, it was said to be distin- 

 guishable from that species by differences in the undulating membrane. Lambl's 

 C. intestinalis 1 (of 1875) which corresponds with C. hominis, Davaine 2 (1854), is 

 regarded by Leuckart as a true Cercomonad (characterized by a flagellum and the 

 absence of an undulating membrane, see p. 61), and is thus generically distinct 

 from Trichomonas, 



The correctness of Leuckart's judgment in regard to Marchand-Zunker's flagellate 

 was demonstrated by Grassi's researches, accounts of which were published soon 

 after. In about 100 cases of bowel complaints in North Italy and Sicily, Grassi 

 found Flagellata in the stools, which he first named Monocercomonas and Cimceno- 

 monas, but later termed Trichomonas. However, in opposition to Leuckart, Grassi 

 has also classified Uavaine's C. hominis ( C. intestinalis, Lambl, 1875) as 

 Trichomonas, and most authors have followed his example. Hence arose the use 

 of the name Trichomonas hominis. It was through Janowski (1896) that the 

 former view was again taken up. After a review of the literature, the occur- 

 rence of Cercomonads in the intestine of human beings in addition to Tricho- 

 monads was considered by the author to have been proved, and he added a 

 description of the Trichomonads. According to this, all morphological distinction 



1 Under the term Cercomonas intestinalis, Lambl in different years has described two 

 entirely distinct Flagellata, namely, in 1859 ("Mikr. Unters. d. Darm- Excrete," Pvag. 



Vierteljahrsschr. f. prakt. Hlkde., Ixi, p. 51 ; and Lambl, A. d. Franz-Josephs-Kinderspitale 

 in Prag, Prag, 1 860, i, p. 360), a form that at the present day is termed Lamblia intes- 

 tinalis ; and in 1875 ( m the Russian Medical Report, No. 33), a species identical with 

 Cercomonas hominis, Dav. 



2 Davaine, C. , " Sur les anim. infus. trouv. dans les selles d. malad. atteints du cholera 

 et d'autr. malad.," C. R. Soc. Biol., 1854, ii, p. 129. 



