GENERAL BIOLOGY 



VII. GELATINE PLATE CULTURE FROM HYDRANT WATER. 



Are colonies present on the plate? If so, how many? Are they all 

 alike in shape and color? What kinds of organisms are found in 

 the different colonies? Are they more or less numerous than in 

 air or milk? 



VIII. AGAR PLATE CULTURE FROM MILK. 



w*~- 



By means of a "counting plate" determine the approximate 

 number of colonies present in the agar, and calculate the number 

 of bacteria present in I cc. of undiluted milk (the I cc. of milk 

 used in the culture was diluted 100 to i). Colonies which have 

 the form of minute footballs belong to the group of "colon bacilli" 

 and come from the intestinal tract of some mammal, in this case 

 probably from a cow. If colon bacilli are numerous it indicates 

 that the milk has not been taken under sanitary conditions. What 

 does the changed color of the litmus agar indicate ? 



C. DEMONSTRATIONS. 



I. Living Bacteria Seen With Dark-Field Illumination., 

 II. Prepared Slides of Pathogenic Bacteria. 



F. -PROTOZOA 



One-celled animals in which the entire body consists of a single 

 cell, which may be independent or may be joined with others to 

 form a colony. 



i. PARAMECIUM CAUDATUM, Slipper Animalcule 

 (Phylum Protozoa, Class Infusoria, Order Ciliata.) 



Read : Calkins, Biology, pp. 60-75 '> or 



Parker, Elementary Biology, pp. 106-120; or 

 Parker and Parker, Practical Zoology, pp. 261-286; or 

 Sedgwick and Wilson, General Biology, pp. 168-172; or 

 Woodruff, Foundations of Biology, pp. 39-43, 244-248, 

 340-342. 



A. MORPHOLOGY. 



Put a small drop of water containing Paramecia on a slide; sur- 

 round it with cotton wool to limit the movement of the animals 

 and cover with a glass ; examine with the low power of the micro- 

 scope and then with the high power. Note: 



[37] 



