xvi REMARKS TO INSTRUCTORS 



and the theories of the factors conditioning this evolution 

 are analyzed. 



V. The History of Zoology and Its Unsolved Problems are indicated 

 in connection with the various other topics, not segregated 

 in the course. 



In a course of this nature we believe that the principles of zoology 

 can be taught more effectively than by any other method of approach. 

 There is no getting away from the fact that the study of an animal in 

 its entirety, rather than a piece at a time, is the most convenient form 

 of laboratory organization. It is also, as we believe, the most effec- 

 tive method of teaching principles, because it makes possible the in- 

 tensive study of the single case and subsequent extension of the prin- 

 ciple to other cases, which is more effective than smattering studies 

 of many forms with the resulting confusion in the mind of the student. 



Contrary to the arrangement of many courses, the vertebrate ani- 

 mal, as represented by the frog, is used as the introductory type. We 

 justify this procedure on the following grounds. In studying the frog, 

 the student is examining vertebrate structure and function in general 

 and is able to utilize the biological knowledge he already has concern- 

 ing his own body and the bodies of familiar animals. Experience 

 indicates that the great majority of students know more biological 

 facts in the vertebrate field than anywhere else. They are at least 

 upon familiar ground, even though most of their supposed information 

 concerning human anatomy and physiology may prove to be inaccu- 

 rate. Moreover, it is not necessary to have the class learn the use of 

 the microscope at the same time that they are becoming accustomed 

 to the special procedure of the laboratory, which is new and difficult 

 for many individuals. However, we recognize the fact that the use of 

 a complex animal for introductory purposes is contrary to the practice 

 of many excellent teachers. // it is desired to begin with the Protozoa, 

 these directions can, we think, be used without serious inconvenience, 

 provided attention is given to the jew places where references are made 

 to previous work. A word of general explanation to the class and spe- 

 cific explanations here and there will suffice. Even if the frog is stud- 

 ied at the end instead of at the beginning of a course, there should be 

 no difficulty beyond the fact that the earlier directions are, of neces- 

 sity, somewhat more explicit than the later ones. 



A word may be said regarding our concept of the relationship be- 

 tween laboratory, textbook, and lectures in a course of this nature. 

 It is possible to organize the instruction in a variety of ways. Lec- 

 tures may be made the primary factor around which everything else 



