But with all wild animals, it is a noticeable fact that a course of contact with man continuing over many generations of animal life causes a species so to adapt itself to its new surroundings that it can hold its own far better than formerly. When white men take up a new country, the game, and especially the big game, being entirely unused to contend with the new foe, succumb easily, and are almost completely killed out. If any individuals survive at all, however, the succeeding generations are far more difficult to exterminate than were their ancestors, and they cling much more tenaciously to their old homes. The game to be found in old and long-settled countries is of course much more wary and able to take care of itself than the game of an untrodden wilderness; it is the wilderness life, far more than the actual killing of the wilderness game, which tests the ability of the wilderness hunter. [Illustration: ABERNETHY RETURNS FROM THE HUNT From a photograph, copyright, 1905, by Alexander Lambert, M.D. ] After a time, game may even, for the time being, increase in certain districts where settlements are thin. This was true of the wolves throughout the northern cattle country, in Montana, Wyoming, Colorado, and the western ends of the Dakotas. In the old days wolves were very plentiful throughout this region, closely following the huge herds of buffaloes. The white men who followed these herds as professional buffalo-hunters were often accompanied by other men, known as wolfers, who poisoned these wolves for the sake of their fur. With the disappearance of the buffalo the wolves diminished in numbers so that they also seemed to disappear. Then in the late eighties or early nineties the wolves began again to increase in numbers until they became once more as numerous as ever and infinitely more wary and difficult to kill; though as they were nocturnal in their habits they were not often seen. Along the Little Missouri and in many parts of Montana and Wyoming this increase was very noticeable during the last decade of the nineteenth century. They were at that time the only big animals of the region which had increased in numbers. Such an increase following a previous decrease in the same region was both curious and interesting. I never knew the wolves to be so numerous or so daring in their assaults upon stock in the Little Missouri country as in the years 1894 to 1896 inclusive. I am unable wholly to account for these changes. The first great diminution in the numbers of the wolves is only partially to be explained by the poisoning; yet they seemed to disappear almost everywhere and for a number of years continued scarce. Then they again became plentiful, reappearing in districts from whence they had entirely vanished, and appearing in new districts where they had been hitherto unknown. Then they once more began to diminish in number. In northwestern Colorado, in the White River country, cougars fairly