HRPKESESTATI\ ES ()F AM MM. flDI.A iVA 



vvliich it has conu' in contact. Slioukl a sju'cinicn be fcjund in 

 the act of dividing; by simple jis.sion watch tho process closely. 



One sees only a rolativoly sli^lit amount of visible difTcrcntia- 

 tion exhibited within the protoplasm of the anueba yet all of 

 the essential processes of li/e are in progress as effectively, appar- 

 ently, as in the frog. The amceba takes food and oxygen, dis- 

 tributes them to various parts of its unicellular body, providing 

 the materials for energy liberation and the building of new proto- 

 plasm; it excretes waste, it can move from plac(> to place, respond 

 to stinuili, and reproduce its kind. Physiologically the highest 

 multicellular organism can do no more. Such forms as the 

 anurba, therefore, arc of the greatest interest and value to the 

 student of life. 



Make an enlarged drawing (four inches in diameter) of an 

 amoeba and show those details of structure which you have 

 been able to identify. Indicate the granular appearance by 

 stippling. 



Class Infusoria {Paramcccium. cnudnium). — Becau.se of its 

 relatively large size and the ease with which unlimited supplies 

 of specimens may be secured this animal lends itself to the study 

 of the structure and normal activities of a more complex type of 

 protozoan. Members of the class Infusoria possess both per- 

 manent form and organs of locomotion. These latter are in the 

 form of cilia which are similar in appearance and action to those 

 found upon the surface of the cells lining the roof of the frog's 

 mouth. These permanent locomotor organs of Paramecium 

 afford a striking contrast to the transitory pseudopodia of the 

 amoeba which are formed "when needed" by a local bulging of 

 the protoplasm of the cell. The permanent form is due to the 

 condensation of the ectoplasm, which necessitates a number of 

 permanent organs some of which arc described below. Cilia 

 are responsible for the rapid movements characteristic of this 

 organism. 



With a pipette place a drop of the infusion containing jiaraino- 

 cia on a slide, cover, and examine under low power. Among the 

 various organisms in the preparation, relatively large, slipper- 

 shaped forms will be noted. These are paramecia. ()bs(>rve 

 them carefully to determine from observation whether the body 

 possesses permanence of form. Are there differences in the form 

 of the two ends of the body? What is the relation of the ends 

 to the direction of locomotion? 



