258 DOMESTICATED ANIMALS 



years ago by some reckless experimenters. These marauders 

 were cleared away without good results. Further inquiry 

 made it apparent that the real enemy of these birds was the 

 feralized domestic cat which has gone wild from the house- 

 holds, especially from the many homesteads that have been 

 abandoned. This creature has bred in great numbers and is 

 now threatening the existence of all birds that rear their 

 broods upon the ground. It is hardly possible to exterminate 

 them, for the reason that they are wary, and any systematic 

 hunting of them would prove exceedingly disturbing to the 

 very timid birds. The result is that nearly all these birds have 

 left my land for certain plains near by which are covered with 

 scrub oaks and where there is too little ground life to attract 

 the cats. In that region, though it has an area of about 

 thirty thousand acres, the food is scanty ; the prairie chickens 

 dwelling there are likely to perish for lack of the rose-hips 

 which, in the hill country they have been forced to desert, 

 served to maintain them at times when the ground was cov- 

 ered with snow. 



The lesson which may be drawn from the experience 

 above stated is to the effect that it is necessary to have a pro- 

 tected field of sufficient area, and in the proper conditions 

 to keep the balance of life which arises from the exchange 

 of relations between species in their normal state. Even 

 in ideal reservations where all invasions are excluded, we 

 should have to expect that from time to time certain forms 

 would disappear, their place perhaps being taken by new 

 species which would arise. Such is the manner of the great 

 procession of life. Probably at least twenty and perhaps a hun- 

 dred times as many species as are now living on the earth have 

 perished from it, and before the unimaginable goal is attained 



