THE SIMPLEST ANIMALS 



301 



Mount and examine another slide with some paramecia which 

 have been swimming for a half-hour in carmine-water (powdered 

 carmine mixed with water, or lamp-black in water). The particles 

 of carmine appear to be in droplets of water in the protoplasm of the 

 animal. Notice the action of the lashing cilia upon the particles 



B 



C.TOC 



Inc. 07! 



c.vac. 



FIG. 88. Paramecium. A, from lower surface. B, in optical section. 

 c.vac, contractile vacuoles; f.vac, food vacuole; nu, nucleus; buc.gr, buccal 

 groove; gul, gullet; mth, mouth; cu, cuticle; corf, cortex, outer layer of 

 protoplasm; med, inner layer. (From Parker.) 



of carmine surrounding the animal, and especially the collection of 

 particles in the groove on one side of the body and then their en- 

 trance into the body through a tube or gullet (see arrows in Fig. 88, 

 B). This taking of carmine illustrates how the animal gets food, 

 chiefly bacteria and other small plants or animals. Notice that 

 there is no stomach or other cavity into which food is taken, but 

 simply particles of food surrounded by a film of water are forced 

 into the protoplasm, which is soft and semi-liquid. These food 



