10 DAVID H. BERGEY 



of the subject that is taken up. It is desirable to give the stu- 

 dent a brief explanation as to what he is expected to do or see 

 and how he is to proceed in conducting the laboratory exercises. 

 When the student has carried out a series of laboratory exercises 

 the subject may be developed on a broader plane by a lecture 

 emphasizing the importance of the observations made and their 

 relation to other aspects of the study. 



The almost infinite number of ways in which the bacteria and 

 their activities react upon human life, especially in their relation to 

 the production of disease in plants and animals, and their relation 

 to the various industrial activities, particularly in food production 

 and food preservation, give us inexhaustible material for study in 

 the classroom. The knowledge which the student of bacteriology 

 gains is of such great personal interest and importance that he is 

 easily carried along, step by step, from simple observations to 

 the most complex and vital phenomena of hfe. 



The study of bacteriology serves unusually well for training the 

 powers of observation and judgment. Every lesson is per se an 

 object lesson and one in which the student is not only the ob- 

 server, but, the demonstrator as well. Moreover the remarkable 

 susceptibiUty of the bacteria to environmental influences will 

 permit of each demonstration being modified in a variety of 

 ways. This possibility of varying the demonstrations precludes 

 the probability of a loss of interest on the part of the student. 



It will be profitable to begin a course in general bacteriology 

 with exercises in staining various types of bacteria. The stu- 

 dent should record his results briefly and amplify the record with 

 line drawings of the organisms and cultures studied. In this 

 way he acquires some knowledge of the relative size, grouping, 

 staining reactions, and rapidity of growth of the bacteria. The 

 next step may be the isolation of bacteria in pure culture from 

 mixtures and the cultivation of several species of these pure 

 strains upon the common media employed for this purpose. 

 In the systematic study of a culture the student may follow 

 the general plan of description as contained in the Society card. 

 This will acquaint him with the vocabulary generally employed 

 in this work and will help him to recognize some of the ac- 



