Association and mutual aid are the rule with mammals.  We find social habits even among the carnivores, and we can only name the cat tribe (lions, tigers, leopards, etc.) as a division the members of which decidedly prefer isolation to society, and are but seldom met with even in small groups.  And yet, even among lions “this is a very common practice to hunt in company."(10) The two tribes of the civets (Viverridae) and the weasels (Mustelidae) might also be characterized by their isolated life, but it is a fact that during the last century the common weasel was more sociable than it is now; it was seen then in larger groups in Scotland and in the Unterwalden canton of Switzerland.  As to the great tribe of the dogs, it is eminently sociable, and association for hunting purposes may be considered as eminently characteristic of its numerous species.  It is well known, in fact, that wolves gather in packs for hunting, and Tschudi left an excellent description of how they draw up in a half-circle, surround a cow which is grazing on a mountain slope, and then, suddenly appearing with a loud barking, make it roll in the abyss.(11) Audubon, in the thirties, also saw the Labrador wolves hunting in packs, and one pack following a man to his cabin, and killing the dogs.  During severe winters the packs of wolves grow so numerous as to become a danger for human settlements, as was the case in France some five-and-forty years ago.  In the Russian Steppes they never attack the horses otherwise than in packs; and yet they have to sustain bitter fights, during which the horses (according to Kohl’s testimony) sometimes assume offensive warfare, and in such cases, if the wolves do not retreat promptly, they run the risk of being surrounded by the horses and killed by their hoofs.  The prairie-wolves (Canis latrans) are known to associate in bands of from twenty to thirty individuals when they chase a buffalo occasionally separated from its herd.(12) Jackals, which are most courageous and may be considered as one of the most intelligent representatives of the dog tribe, always hunt in packs; thus united, they have no fear of the bigger carnivores.(13) As to the wild dogs of Asia (the Kholzuns, or Dholes), Williamson saw their large packs attacking all larger animals save elephants and rhinoceroses, and overpowering bears and tigers.  Hyenas always live in societies and hunt in packs, and the hunting organizations of the painted lycaons are highly praised by Cumming.  Nay, even foxes, which, as a rule, live isolated in our civilized countries, have been seen combining for hunting purposes.(14) As to the polar fox, it is—­or rather was in Steller’s time—­one of the most sociable animals; and when one reads Steller’s description of the war that was waged by Behring’s unfortunate crew against these intelligent small animals, one does not know what to wonder at most:  the extraordinary intelligence of the foxes and the mutual aid they displayed in digging out food concealed under