THE PEOTOZOA 



f. The moutli is an oval aperture in the ectosarc at 



the hinder end of the oral groove, through which 

 the food passes into the endosare. 



g. The anus is an aperture between the mouth and 



the hinder end of the body. It is visible only at 

 the moment of extrusion of fsecal matter. 



2. The endosare is the more fluid granular protoplasm 

 forming the central portion of the cell-body. 



a. The food-vaeuoles are spherical spaces in the 



endosare filled with water containing food- 

 particles. 



b. The circulation of the endosare is rendered obvious 



by the food-vacuoles and the granules, which are 

 carried round in a definite direction. 



c. The nucleus is an elongated ovoid body near the 



centre of the cell-body. 



d. The paranucleus is a much smaller body applied to 



oiie side of the nucleus, and resembling it in 

 appearance. In some cases both nucleus and 

 paranucleus appear to be situated in the ectosarc 

 rather than in the endosare. 



1 Reproduction. 



1. Fission is the most usual method, and is effected in the 



following manner. A transverse constriction appears 

 on the surface of the animal, and deepens till the 

 body is divided into two, each having a portion 

 of the original nucleus and paranucleus, and each 

 becoming a perfect Paramecium. 



2. Conjugation is not a mode of reproduction but is 



closely connected with it. Two Paramecia become 

 united by their ventral surfaces, and, after swim- 

 ming about together for some time, separate 

 and become independent again. During and after 



