578 The American Naturalist. [July, 
terms; compactness, accuracy, and intelligibility would all be 
sacrificed if terms were given up. And yet nearly all geogra- 
phers employ paraphrases instead of terms. Let us take an ex- 
ample to illustrate this from the description of certain counties in 
Missouri in one of the geological reports on that state, to which 
as in other states we must generally go for the best geographic 
materials. 
The region is one of horizontal structure, and therefore comes 
under the general heading now considered. Of Miller county it 
is said : ^ " Near the Osage and its larger tributaries, the country 
is generally very broken and rocky, excepting immediately in the 
valleys ; but farther back the slopes usually become more gentle, 
with fewer exposures of rock, until we reach the higher districts, 
more remote from the streams, where the surface is comparatively 
level, or but slightly undulating." Again, of Morgan county : 
" The surface of the elevated region near the middle of the county 
is beautiful, comparatively level or undulating prairie land. South 
of this the slopes are first gentle, near the head branches of the 
Gravois, but as we descend these the face of the country becomes 
more hilly, and almost everywhere near that and the main creeks, 
as well as their principal tributaries, and especially near the 
Osage, it is very broken and rocky. North of the main divide, 
the high, nearly level prairie land extends, with a slight descent, 
for some distance northward between the streams flowing in that 
direction, but near most of the larger streams the surface is more 
or less broken, and sometimes rocky, but generally not so much 
so as on the south side." 
What is meant by this ? Manifestly, the country is an adoles- 
cent plain of moderate intensity of development and apparently 
of simple history. The horizontal attitude of the rocks and the 
level surface of the uplands show us that the region belongs to 
the family of plains or plateaus ; the irregular courses of the 
streams and the steepness of their banks decide with equal clear- 
ness that the development of the plain has not advanced very far. 
Now in the same report the writer says that there are oak trees 
