GENERAL BIOLOGY 



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

 endoplasm filled with water containing food particles. 



(2). The circulation of the endoplasm 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 after the death of the 

 animal, or in stained specimens. 



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

 side of the nucleus and resembling it in staining reactions. 



Make a full-page drawing of an animal to show the above- 

 mentioned 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 Endoplasm. 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 com- 

 pletes the circuit. 



3. Egestion. Observe, if possible, the egestion of ink from the 

 body. Show by a drawing where and how this takes place. 



4. Digestion. Observe and draw the changes in color, etc., of 

 food as the vacuoles circulate through the body, also the changes 

 in the size of vacuoles and their fluid contents. What do these 

 changes indicate? 



5. 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. 



6. Excretion. The contractile vacuoles are excretory organs 

 for getting rid of water and nitrogenous waste (urea). Study and 

 sketch a vacuole in various stages of contraction and expansion. 

 Time the contractions and expansions and record the results in 

 your notes. Place Paramecia in a thick solution of Chinese ink 



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