Examples of Pupils' Work 181 



by the small locomotive cilia, (b) The peristome or 

 8-shaped line of large cilia at the anterior end of the body, 

 by the action of which the indigo is swept in. (c) The 

 vestibule, a widely opened funnel-shaped chamber lined 

 with cilia and situated in the posterior end. (d) The 

 oesophagus, a ciliated tube which leads downward and 

 backward into the substance of the endoplasm. In this 

 tube the particles of indigo are gradually rolled into a 

 pellet, and from time to time these pellets are forced, by 

 contractions of the body, out of the inner end of the tube 

 into the endoplasm. One of the pellets, together with a 

 little water swallowed with it, forms a food vacuole, of 

 which several may be seen in different parts of the body. 

 A food vacuole is a spherical space filled with water and 

 containing solid particles of various kinds. As the vacuoles 

 are carried around the body by the circulation of the 

 endoplasm, the water and the soluble parts are digested 

 out, until at last only the indigestible parts remain embedded 

 in the body substance as a food-ball. After a time these 

 particles accumulate at a point upon the dorsal surface 

 about half way between the vestibule and the posterior 

 end of the body. The ectoplasm becomes thin over them, 

 and they are then driven out of the body through a tem- 

 porary anus. These animals have no sense of taste, as 

 indigestible particles are readily taken in. 



Its respiration is carried on through the external surface 

 of the body. It has no special respiratory organs, but it 

 absorbs food and air from the currents of water passing 

 through it or bathing the surface of its body. 



The circulation of the food is carried on by the con- 

 Tactile vacuoles. As they contract they force the food 

 out into the surrounding mass. 



d. Reproduction, conjugation, division, etc. Reproduc- 

 tion in the Paramecium is a simple process of transverse 

 binary fission. Both macronucleus and micronucleus 

 elongate prior to the division of the cell-body and undergo 

 mitosis. They first become fusiform, and at either pole 

 of the spindle plates are formed connected by fibrils running 

 the whole length of the spindle. The spindle, then elon- 

 gated, becomes dumb-bell shaped, and the two swollen 

 ends are connected by a fine thread, which soon snaps in 



