The young, varying from one to eight in number, are born in April or May. At first they are naked and helpless, but when large enough accompany the mother on her search for food. This period of schooling lasts until they are forced to take up their separate lives with the approach of winter. Thenceforth they are among the most solitary of animals, showing fierce antagonism toward one another whenever they meet, and associating only during a brief period in the mating season in February or March. Martens show a cold-blooded ferocity toward one another that often renders it dangerous to put two or more in the same cage. When placed in a cage together the male very commonly kills the female by biting her through the skull. At times they utter a loud, shrill squall or shriek, and in traps hiss, growl, and sometimes bark. Among the dense forests of spruce and lodge-pole pine high up in the mountains of Colorado, martens are sometimes hunted on skis in midwinter, an exciting and often, on these rugged slopes, a dangerous sport. They are not wary about traps and are readily caught by deadfalls and other rude contrivances as well as by steel traps. In Colorado and Montana hundreds of their skins are taken by trappers every winter. In Siberia the sable has been exterminated by hunting in many districts, and before the present war began had become so scarce in others that the Russian Government closed the season for them for a period of years over nearly all of their range. The same reduction in the numbers of our marten has occurred in most parts of Alaska and elsewhere in its range, and its only hope against extermination lies in stringent protection. Protective regulations are already in force in Alaska. During the early fur-trading days in northern Canada the number of martens varied between comparative abundance and rarity. These variations were said to occur about every ten years. Some claimed the decrease was due to a migration which the martens were believed to make from one region to another, just as was believed of the lynx. The lack of a corresponding increase in surrounding districts, where trading posts were located, effectually disproved the migration theory. There is little doubt that the increase of martens was due to a reproductive response to a plentiful food supply during years when mice or snowshoe hares were abundant and their decrease was due to a lessening of the numbers of these food animals. Efforts are being made to domesticate martens and raise them for their skins on fur farms. The main difficulty so far encountered lies in the fiendish manner in which the old males kill the females and the younger males. Although always nervous, they are not difficult to tame, and will be most entertaining and attractive animals to rear if their savage natures can be sufficiently overcome. =THE LITTLE SPOTTED SKUNK= (=Spilogale putorius= and its relatives) (_For illustration, see page 558_)