4OO SPECIFIC MICRO-ORGANISMS 



Trichomonas Hominis. Davaine observed this parasite in 

 1854. It is common in the human digestive tract, especially in 

 the stomach in anacidity and in the intestine in chronic digestive 

 disturbances. The organism is 3 to 4/z wide and 4 to i5/z long, 

 pear-shaped and provided with three free flagella, and a fourth 

 thread which passes around one side of the cell in the margin of 

 the undulating membrane. The parasite seems to be a harmless 

 commensal, as a rule, but it may possibly bear some causal rela- 

 tion to diarrhea in some cases. Animals have not been success- 

 fully inoculated with it. Tr . vaginalis is very similar. It grows 

 in the acid vaginal mucus. Other trichomonad forms occur in 

 the intestines of animals, particularly in mice, in frogs and in 

 lizards. 



Lamblia Intestinalis.- The cell has the form of a turnip with 

 a wide and deep excavation in front near the anterior rounded 

 end, forming a suction cup. The body is bilaterally symmetrical. 

 The length is 10 to 2i/z and the width 5 to i2ju. There are eight 

 flagella, each from 9 to 14/1 long. The mode of multiplication is 

 not fully known. Resistant cysts are formed, probably after 

 sexual union of two individuals, and these escape with the feces 

 and lead to the infection of new hosts. Lamblia lives in the duo- 

 denum and jejunum of man and many other mammals. It ap- 

 pears to be relatively harmless in most cases but the possibility 

 that it may be a cause of digestive disturbance must be con- 

 sidered. It is often present in chronic dysenteries. 



Mastigamceba Aspera. This a saprophytic form, described 

 by Schulze, which possesses a single flagellum, but is also capable 

 of extending finger-like projections of its cytoplasm, pseudopodia, 

 just as an ameba does. Whitmore 1 has described a somewhat 

 similar saprophyte, Trimastigamceba philippinensis, which is at 

 times ameboid without flagella and at other times possesses three 

 or possibly four whips. It divides and encysts like an ameba. 

 The organism is readily cultivated on the alkaline agar of Mus- 

 grave and Klegg. 



1 Archivf. Prolistenkunde, 1911, Bd. XXIII, S. 81-95. 



