166 THE POPULAR SCIENCE MONTHLY 
manently valuable as we know how, to the ecologist as well as the sys- 
tematist. It is quite probable that the facts of distribution, life history, 
and economic status may finally prove to be of more far-reaching 
value, than whatever information is obtainable exclusively from the 
Specimens themselves. 
At this point I wish to emphasize what I believe will ultimately 
prove to be the greatest value of our museum. This value will not, 
however, be realized until the lapse of many years, possibly a century, 
assuming that our material is safely preserved. And this is that the 
student of the future will have access to the original record of faunal 
conditions in California and the west wherever we now work. He will 
know the proportional constituency of our faune by species, the rela- 
tive numbers of each species and the extent of the ranges of species as 
they exist to-day. 
Perhaps the most impressive fact brought home to the student of 
geographical distribution, as he carries on his studies, is the profound 
change that is constantly going on in the faunal make-up of our coun- 
try. Right now are probably beginning changes to be wrought in the 
next few years vastly more conspicuous than those that have occurred 
in ten times that length of time preceding. The effects of deforesta- 
tion, of tree-planting on the prairies, of the irrigation and cultivation 
of the deserts, all mean the rapid shifting of faunal boundaries, the ex- 
tension of ranges of some animals, restriction in the ranges of others, 
and, with no doubt whatever, the complete extermination of many 
others, as in a few cases already on record. 
If we now had the accurate record of faunal conditions as they were 
in the Atlantic states a century ago, how much might we not be able 
to adduce from a study of the changes which have taken place. Now is 
the opportunity to make such records in our western region. Compar- 
ative studies of conditions in the same area at different successive times 
is bound to bring important generalizations in the field of evolution. 
It will be seen here how valuable also will prove the collections pre- 
served at corresponding intervals. Changes in conditions will doubtless 
bring about changes in the habits and physical characters of the ani- 
mals enduring them. 
Another grave danger from the standpoint of the student of natural 
speciation lies in the introduction of exotic animals. This evil is grow- 
ing rapidly in the effort to restock regions with more hardy or prolific 
game animals. If successful from the sportsman’s basis, either of two 
things will happen: the original, native species will become extinct by 
competitive replacement, or, where the relationships are close, crossing 
will take place so that the original species will be spoiled through 
hybridization. There are already instances of both in different sec- 
tions of the United States. It is highly desirable that a good repre- 
