Topographic Forms. — Pern/. 153 
A CLASSIFICATION OF TOPOGRAPHIC FORMS.* 
By Stuart H. Perry. Pontiac, Mich. 
The study of topographic forms in their relations to the 
geological processes by which they are produced and modified 
has only in recent }^ears risen to the importance of a distinct 
branch of geology. This new science, which may, perhaps, be 
most fitly termed Geoinorphy, is distinctively American. I do 
not mean that it is exclusively American, but its development 
is due largely to the labors of geologists of this country. It 
is natural that it should have attained such prominence here 
because Nature has furnished us unexampled opportunities 
for its study, and it has received the attention of many able 
scientists. But while much has been written more or less 
indirectly, the information is widely scattered and the subject 
has generally been treated only in part and in its more inti- 
mate relations with certain phases of geology proper. It is 
only quite recently that certain writers, such as McGee and 
Davis, have taken up the subject in its more general and in- 
dependent relations. Professor Davis has already given in a 
number of excellent papers a general view of the science in 
its present state, and has shown the great importance of geo- 
logical methods* in the consideration of this neutral ground 
between geology and geography. I need not, then, dwell on 
the subject in its broader relations, but will take up at once 
the problem which this paper endeavors to solve. 
The problem of the classification of topographic forms is 
one of the most important in Physical Geology, and few at- 
tempts have yet been made at its solution. No entirely sat- 
isfactory classification has yet been proposed. The great 
number and diversity of topographic forms, and the many 
causes and combinations of causes to which they are due. 
render it nearly impossible to devise a system that will be at 
once scientific and practical. The requirements of such a 
system are the same as those of any other classification; 
namely, that it shall be inclusive, that its divisions shall be 
natural and not arbitrary, and that it shall be concise and 
*This paper was originally written, in a somewhat different form, as 
a thesis forming a part of the course in Physical Geology in the Uni- 
versity of Michigan. The author is indebted to professor Russell, un- 
der whom the work was done, for many suggestions, and has made use 
chiefly of the works of Davis, McGee, Gilbert, Russell, Powell, Dutton. 
Chamberlin, Upham, Hitchcock and De LaNoe and Margerie. 
