end of the groove through which food passes into the endosarc. 

 Watch the ink collect at the inner end of the gullet into a ball 

 which is suddenly passed into the endosarc. Watch the course of 

 the food ball around the body until it is finally ejected. 



(7). The anus is a temporary aperture between the mouth and 

 the hinder end of the body visible only at the moment of ejection 

 of fecal matter. 



b. The Endosarc (Medulla) is the more fluid protoplasm filling 

 the central portion of the body. 



( i ) . The food vacuoles are spherical spaces in the endosarc 

 filled with water containing food particles. 



(2). The circulation of the endosarc is rendered obvious by the 

 food vacuoles and the granules, which are carried round in a 

 definite direction. 



(3). The nucleus is an elongated oval body near the center of 

 the body of the animal. It is best seen with light reflected from the 

 slide, not from the mirror, or in stained specimens. 



( 4 ) . The micronucleus is a much smaller body applied to one 

 side of the nucleus and resembling it in appearance. 



J\Iakc one or two drawings of an animal to shoiv the above men- 

 tioned structures. 



B. PHYSIOLOGY. 

 I. METABOLISM. 



1. Ingestion of food. Place some Paramecia on a slide with 

 powdered Chinese ink and watch the formation of food balls in the 

 gullet and their ingestion. Study the formation of a food vacuole. 



2. Circulation of Endosarc. Observe and sketch the changes of 

 position of the food vacuoles in the body and show by arrows the 

 course of circulation. Time the circulation by noting the time at 

 which the ink is added and that at which the first ink ball completes 

 the circuit. 



3. Nature of food. Study the nature of the contents of the food 

 vacuoles of normal Paramecia and find, if possible, what they feed 

 upon. Is it animal or vegetable matter? Does Paramecium choose 

 its food? Stain with iodine and see if any starch is used as food. 



4. Digestion. Observe the changes in color, etc., of food as it 

 passes through the body, also the changes in the vacuoles and their 

 fluid contents. What do these changes indicate? 



5. Egestion. Observe, if possible, the egestion of ink from a 



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