PROTOZOA. 

 Fig. 1} 



The first species (marked 1 in the woodcut) some- 

 times exists in very considerable numbers in the 

 recent evacuations of persons affected with cholera ; 

 the second species of the animalcule (marked 2 in the 

 woodcut) is smaller than the preceding ; it has been 

 observed in the dejections of patients suffering from 

 typhoid fever. 



(c.) Genus Trichomonas. — This very minute ani- 

 malcule is similar in appearance to the two genera 

 just described ; it differs, however, in possessing an 

 anterior flagelliform filament, surrounded by a group 

 of vibratile cilia. The Trichomonas Vaginalis has 

 been observed in the vaginal mucus. Trichomonad 

 protozoa are often united together in groups com- 

 posed of about five or six individuals, of which only 

 the moving flagelliform appendages can be distin- 

 guished. When the mucus becomes reduced in 

 temperature they quickly perish and disappear. 



3. Paramecia. — Protozoa having a soft, flexible 

 body, of variable form, usually oblong, more or less 

 flattened, and provided with a reticulated integu- 

 ment, which is loose, and covered with numerous 

 vibratile cilia, arranged in a regular series ; each 

 Paramecium possesses a distinct intestinal tube ; the 

 movements of these animalcules are rapid, and some- 

 times gyratory. 



The Paramecium Coli has been found in the 

 human colon, and in the evacuations. 



* Explanation of Figure 1. — The Cercomonas liominis mag- 

 nified 850 times. The two varieties are marked respectively 

 1 and 2. 



