432 
The Ohio Naturalist. 
[Vol. VI, No. 3, 
Again, when in physiography he studies the life history of a 
plateau and traces the feature from its geotectonic uplift through 
the steps of its dissection and aging, watching its valleys first 
deepen, then widen, and its level topped divides melt away to 
crests with long slopes, while the valley floors widen to occupy 
half or two-thirds of the region, he may incidentally note that 
the population and highways occupy the tops of the hills — the 
plateau siirface — in youth, that the culture descends the slopes 
as the valleys mature, and that in maturity transportation 
routes, cities, and most of the people are in the valleys while the 
hill tops are left to pasture or forest. To sum up, a few facts in 
either science are gathered in the pursuit of the other, but the 
two subjects do not develop concurrently. 
To the second question, “which should receive the attention 
first,” the answer depends upon the age and maturity of the 
pupil. If a child, geography first everytime. If a mature 
student, he may well prepare for geography by a strong course 
in physiography ; but the phenomena, reasoning, and philosophy 
of the latter are far beyond the experience and power of the 
child, to say nothing of the locus of his interest. 
The remaining question, “can one be studied without the 
other,” has been at least partly answered. In physiography, 
one does not need to learn many facts of geography, and he cer- 
tainly ought not to follow up the relations to man and his 
responses to the influence of the conditions, far enough to detract 
from the systematic development of his subject. In geography, 
he uses the facts of this related science as he does those of 
historv, sociology and anthropology, but he does not attempt 
to grasp its philosophy. 
Turning to the second division of the subject, “their differ- 
ences” it is apparent from what has preceded that they often 
deal with the same features and phenomena. They seem in 
many topics to use the same basal materials but in a different 
way. For illustration — in physiography the valley is a topic. 
It is described, its origin and the evolution of its parts are dis- 
cussed. Its development is traced and a definite age is ascribed 
to it. Its end is predicted. Its genetic relation to the sur- 
rounding region is discussed. In geography, the same valley is 
noted as a control of the movements of men and goods, as a 
home for a state, clan or a certain group of men, or as the seat 
of ada])ted industries. Its commercial or economic relations to 
the surrounding region are noted. 
Another illustration is furnished by the river. In ph}’siogra- 
phy, its course through the valley and the regional topography 
is considered ; the work accomplished in its normal development ; 
its method of ]wocedure in carving its valley, enlarging its 
