14 
IOWA ACADEMY OF SCIENCE 
the farthest twigs ; we have the San Juan and other islands of the Sound, 
hills and mountains of glaciated rock, now largely submerged by the 
sea; we have the Olympic mountains with their unusual rainfall and 
constant exposure to the western ocean; in all these places there are 
peculiar plant-formations and generally species and types unique to the 
locality. 
The prairie districts, already referred to, appear to have been pri- 
marily regions treeless or nearly so, and treeless for probably different 
reasons in different localities. Thus the famous Steilaeoom prairie, 
already described, probably owed its treelessness to the thinness of its 
stony soil. It seems to have been when first observed, dotted every- 
where with a peculiar oak, Quercus garryana Douglas, isolated or in 
small clusters, hardly groves. Single aged trees of this species here are 
two or three feet thick, but short and evidently stunted. They seem 
part of a xerophytic flora, and in the text of the Tacoma Quadrangle 
Folio U. S. Geol. Surv. 1899, the Steilaeoom gravels are put down as 
entirely sterile. The old resident, however, reports that thirty or forty 
years ago these same gravels bore crops of wheat for a succession of 
years. After the fashion of Pacific coast farming, the oaks w T ere not 
removed. Continuous cropping without rotation probably soon ex- 
hausted the little fertility for wheat. However this may be, the soils 
are now considered fertile; and strange as it may seem the Douglas 
spruce is rapidly and snrely occupying all the prairie; the fallowed 
wheat-lands offering to the spruce seed, evidently, opportunity which 
the original surface with its competing flora did not afford. Further- 
more, the aggressive immigrants have developed a habit of early matur- 
ity Ycry surprising, almost varietal in character, trees six to ten feet 
high may be seen covered with cones. Is this a xerophytic response? 
The Steilaeoom plain is furthermore marked by beautiful glacial 
lakes, just like those of northern Iowa, and about these lakes are 
fringes of coniferous forest presenting the species characteristic of the, 
country in usual form. This also is an interesting fact whose explana- 
tion remains for future study. 
Space suffices not to enter upon all the problems suggesting themselves 
to one tramping for weeks about these plains and hills. To some of these 
with your permission, the writer may seek to call your attention at 
some future day. But the great, the literally overshadowing factor, in 
all this western world is the forest itself, great in every sort of economy, 
ecologically, biologically, sociologically, wonderful in its scientific as- 
pects, nor less in that which concerns the welfare of men. This great 
Puget Sound forest is still a phenomenon in itself and may well occupy 
us for the few remaining pages permitted to this paper. 
