1 66 TEE 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 faunas 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. Eight 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- 



