PARAMECIUM 3 



0. Movements. 



The constant but slow change of form already referred 

 to is kno-wn as ' amoeboid movement.' Pseudopodia are 

 protruded from any point of the surface, and can be com- 

 jiletely withdrawn, and a slow crawling movement of the 

 whole animal can be effected by their means. Pseudopodia 

 may also surround particles of food and then be withdrawn, 

 bringing the food-particles into the body. 



Draw a specimen of Amoeba several times at intervals of 

 half a minute, indicating the direction of flow of the particles 

 by means of arrows. Compare the drawings, and note the 

 differences of form even in sluggish specimens in which move- 

 ment was not obvious. 



Feed with indigo or carmine, or other finely divided 

 pigment, and note that food is taken in at all pa/rts of the 

 swrface. 



D. Beproduction. 



Amceba multiphes by fission; that is, the whole mass 

 divides iato two, each containing a portion of the nucleus, of 

 the endosarc, and of the ectosarc of the original cell. 



II. PAEAMECIUM AUBELIA. 



This is a free -swimming freshwater protozoon found 

 abundantly amongst decaying vegetable matter. It differs 

 from Amoeba in its more definite shape ; in the more marked 

 differentiation of ectosarc and endosarc; in the presence of 

 cilia and the absence of pseudopodia ; in its active locomotion 

 by means of the cilia; and in the possession of a definite 

 mouth, and of definite dorsal and ventral surfaces, and ante- 

 rior and posterior ends. 



Put a drop of water containing Param^cia on a slide ; 

 spread a very little cotton wool over it, to limit the move- 

 ments of the animals ; cover, and examine with low and high 



powers. 



b2 



