ST'GGESTED ^[ETHODS OF TEACHING 381 



hiring, it is first necessary to find tlie faults in our systems. No topic 

 in historical geology is more abused than that of paleogcography. This 

 is true because most teachers do not realize how uncertain are the bound- 

 aries of the lands and seas on the published paleogeographic maps. The 

 result is that students are sometimes required to learn a great deal that 

 is based on very uncertain evidence or much that will later be changed, 

 or which may already liave been abandoned by those who are working 

 on the subject. 



There are two suggestions for the teaching of paleogcography to ele- 

 mentary students that are at least worth our consideration. One is that 

 the paleogcography of a single period should be chosen as a type and 

 should be thoroughly studied. In this way the student would get a 

 better grasp of the changes in geography that have taken place in a 

 single period, and from this as a type could form a better idea of the 

 paleogcography of other periods. A second suggestion is that the regions 

 of general submergence should be emphasized. The method usually 

 adopted is to require the student to learn the boundaries between the 

 seas and lands of each period as given in the most recent paleogeographic 

 maps. As in the study of invertebrates, the teacher must put himself in 

 the place of the student and ask himself, "Is all of the work required 

 worth the student's time and effort?" If it is found that some of it is 

 not, it should, of course, be omitted or rearranged. It is evident that 

 the paleogcography of the region in which the college or university is 

 situated should be emphasized. One obstacle in selecting the material 

 to be presented is that few geologists have an extended knowledge of 

 paleogcography, and consequently do not know what is hypothetical and 

 what is based on fact. 



Conclusions 



I do not wish to touch on a controversial subject, but one can not 

 fairly dismiss the topic before us without doing so. I refer to the seem- 

 ingly growing practice of permitting a student to elect either physical 

 geology or physiography as a first course, and later allowing the same 

 student to choose as a second course whichever of these two he had not 

 taken. Any one who has looked over the text-books of physical geology 

 and physiography must be impressed with the large amount of material 

 in the one which is duplicated in the other. Certainly one-half, possibly 

 three-fourths, of the subject-matter is the same in the two. It is not my 

 purpose to discuss the advisability of eliminating the one or the other 

 of these courses, but to ask you to think about this question : Would nor 



