48 THE ANIMAL PARASITES OF MAN 



clinic occupied by four children, three who partook of the general 

 diet as well as of water fell ill of diarrhoea with Trichomonades, 

 whereas the fourth child, who did not drink water, remained well. 

 When, however, this child, as a matter of experiment, was twice 

 given 250 c.cm. of the same water that the other children had 

 had, he likewise became ill. According to another opinion the 

 Trichomonades are innocuous inmates of the intestines of many 

 healthy persons, and appear alive in the fasces whenever, from any 

 cause, there is increased peristaltic action of the bowels. It is, 

 however, not beyond the bounds of possibility that in intestinal 

 disturbances, the Trichomonades, by increasing rapidly, may aggra- 

 vate, or at least protract, the morbid process. 



May, Roos, 1 and Schiirmayer- state that they have seen 

 encysted forms, but it is not certain whether these really belong 

 to Trichomonas. 



Kunstler has published an account of the more minute struc- 

 ture of the Trichomonades (Observ. sur le Trich. intest. in Bull, 

 scientif. de la France et de la Belg., 1898, xxxi.). 



Gen. 2. Lamblia, R. Blanch., 1888. 



Syn., Dimorphus, Grassi, 1879, nee Haller, 1878 ; Megastoma, Grassi, 1881, 

 nee de Blainville. 



The body is pear-shaped, with a hollow on the inferior surface directed to 

 the front. It has four pairs of flagella directed backwards, of which three 

 pairs lie on the borders of the hollow, and the fourth arises from the pointed 

 posterior extremity. 



i. Lamblia intestinalis (Lambl), 1889. 



Syn., Cercomonas intestinalis, Lambl, 1859 (nee 1875) > Hexamitus 

 duodenalis, Davaine, 1875 ', Dimorphus muris, Grassi, 1879 ; Megastoma 

 entericum, Grassi, 1881 ; Megastoma intestinale,R. Blanch., 1886. 



Length, o-oi 0-021 mm. ; greatest breadth, 0*005 0-012 ; 

 flagella of about equal length (0-009 0^014 mm.). 



The body is finely granular and has a very thin cuticle, 

 which does not entirely prevent changes of form of the body ; 



1 Roos, E., " Ueb. Infus.-Diarrhoe " (Dtsch. Arch. f. klin. Med., 1893, li., p. 505). 



- Schiirmayer, B., " Ueb. d. York. d. Flagell. i. Darmk. d. Mensch." (C. f. B. u. P., 

 1895, i, xviii., p. 324). For further literature see Janowsky (/. c.). To Schiirmayer 

 the credit is due of rediscovering the Trichomonade of the human intestine, although 

 in the single work which he consulted, Leuckart's Trichomonas intestinalis is men- 

 tioned a few lines before the place he referred to, and on the same page (Leunis, 

 Svnops. bearb. v. H. Ludwig, 1886, ii., p. 1125). Fortunately chance led our author 

 to use the same name for his apparently new species, although in it he did not find the 

 undulating membrane. 



