American Big Game in Its Haunts: The Book of the Boone and Crockett Club. Various
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is well shown in this order, for its subdivisions rest less upon a few well defined characters than upon complex associations of a number of lesser and more obscure ones, a recapitulation of which would be tedious beyond the endurance of all but practiced anatomists. For the present purposes it must be enough to say that bears and dogs have forty-two teeth in the complete set, of which four on each side above and below are premolars, and two above, with three below, are molars, but these teeth in bears have flatter crowns and more rounded tubercles than those of dogs, and the sectorial teeth are much less blade-like, this style of tooth being better adapted to their omnivorous food habits. Bears, furthermore, have five digits on each foot and are plantigrade, while dogs have but four toes behind and are digitigrade. These differences are less marked in some of the smaller arctoids, which may have as few as thirty-two teeth, and come very near to dogs in the extent of the digital surface which rests upon the ground in walking.
In distinction from these, Aeluroidea never have more than two true molars below, and the cusps of their teeth are much more sharply edged, reaching in the sectorials the extreme of scissor-like specialization. In all of them the claws are more or less retractile, and they walk on the ends of their fingers and toes.
Cats are distinguished from the remainder of this section by the shortness of the skull, and reduction of the teeth to thirty, there being but one true molar on each side, that of the upper jaw being so minute that it is probably getting ready to disappear.
Civets, genets, and ichneumons are small as compared with most cats; they are fairly well distinguished by skull and tooth characters; their claws are never fully retractile, and many have scent glands, as in the civets. No member of this family is American.
Hyaenas have the same dental formula as cats, but their teeth are enormously strong and massive, in relation to their function of crushing bone.
No carnivore has teeth so admirably adapted to a diet of flesh as the cat, and, in fact, it may be doubted if among all mammals, it has a superior in structural fitness to its life habits in general.
The Felidae are an exceedingly uniform group, although they do present minor differences; thus, some species have the orbits completely encircled by bone, while in most of them these are more or less widely open behind; in some the first upper premolar is absent, and some have a round pupil, while in others it is elliptical or vertical, but if there is a key to the apparently promiscuous distribution of these variations, it has not yet been found, and no satisfactory sub-division of the genus has been made, beyond setting aside the hunting-leopard or cheetah as Cynaelurus, upon peculiarities of skull and teeth.
True cats of the genus Felis were in existence before the close of the Miocene, and yet earlier related forms are known. Throughout the greater part of the Tertiary the remarkable type known as sabre-toothed cats were numerous and widely spread, and in South America they even lasted so far into the Pleistocene that it is probably true that they existed side by side with man. Some of them were as large as any existing cat and had upper canines six inches or more in length. Cats have no near relations upon the American continent, nor do they appear to have ever had many except the sabre-tooths. Of present species some fifty are known, inhabiting all of the greater geographical areas except Australia. They are tropical and heat loving, but the short-tailed lynxes are northern, while both the tiger and leopard in Asia, and puma in America, range into sub-arctic temperatures, and it is a curious anomaly that while Siberian tigers have gained the protection of a long, warm coat of hair, pumas from British America differ very little in this respect from those of warm regions.
No other cat has so extensive a range as Felis concolor and its close allies, variously known as puma, cougar and mountain lion, which extends from the Atlantic to the Pacific, and from latitude fifty-five or sixty north, to the extreme southern end of the continent. As far as is known, it is a recent development, for no very similar remains appear previous to post-tertiary deposits.
Bears of the genus Ursus are of no great antiquity in a geological sense, for we have no knowledge of them earlier than the Pliocene of Europe, and even later in America, but fossils becoming gradually less bear-like and approximating toward the early type from which dogs also probably sprung, go back to the early Tertiary creodonts.
Cats, as we have seen, are chiefly tropical, while bears, with two exceptions, are northern, one species inhabiting the Chilian Andes, while the brown bear of Europe extends into North Africa as far as the Atlas Mountains.
The family Procyonidae contains the existing species which appear to be nearest of kin to bears. These are all small and consist of the well-known raccoon, the coatis, the ring-tailed bassaris and the kinkajou, all differing from bears in varying details of tooth and other structures. The curious little panda (Aelurus fulgens) from the Himalayas, is very suggestive of raccoons, and as forms belonging to this genus inhabited England in Pliocene times, it is possible that we have pointed out to us here the origin of this, at present, strictly American family; but, on the other hand, evidence is not wanting that they have always been native to the soil and came from a dog-like stock.
As we have already seen, bears have the same dental formula as dogs, but as they are less carnivorous, their grinders have flatter surfaces and the sectorials are less sharp; in fact they have very little of the true sectorial character. It is unusual to find a full set of teeth in adult bears, as some of the premolars invariably drop out.
It is fully as true of bears as of any other group of large mammals, that our views as to specific distinction are based upon data at present utterly inadequate, for all the zoological museums of the world do not contain sufficient material for exhaustive study and comparison. The present writer has examined many of these collections and has no hesitation in admitting that his ideas upon the subject are much less definite than they were ten years ago. It does appear, though, that in North America four quite distinct types can be made out. First of these is the circumpolar species, Ursus maritimus, the white or polar bear, which most of us grew up to regard as the very incarnation of tenacious ferocity, but which, as it appears from the recitals of late Arctic explorers, dies easily to a single shot, and does not seem to afford much better sport than so much rabbit shooting. The others are the great Kadiak bear (U. middendorfi); the grizzly (U. horribilis), and the black or true American bear (U. americanus). The extent to which the last three may be subdivided remains uncertain, but the barren-ground bear (U. richardsoni) is surely a valid species of the grizzly type. The grizzlies and the big Alaska bears approach more nearly than americanus to the widespread brown bear (U. arctos) of Europe and Asia, and the hypothesis is reasonable that they originated from that form or its immediate ancestors, in which case we have the interesting series of parallel modifications exhibited in the two continents, for the large bear of Kamtschatka approaches very nearly to those of Alaska, while further to the south in America, where the conditions of life more nearly resemble those surrounding arctos, these bears have in the grizzlies retained more of their original form. Whether or not the large Pleistocene cave bear (U. spelaeus) was a lineal ancestor is questionable, for in its later period, at least, it was contemporary with the existing European species. The black bear, with its litter-brother of brown color, seems to be a genuine product of the new world.
Many differential characters have been pointed out in the skulls and teeth of bears, and to a less extent, in the claws; but while these undoubtedly exist, the conclusions to be drawn from them are uncertain, for the skulls of bears change greatly with age, and the constancy of these variations, with the values which they should hold in classification, we do not yet know.
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It is not improbable that the reader may leave this brief survey with the feeling that its admissions of ignorance exceed its affirmations of certainty, and such is indeed the case, for the law of scientific validity forbids the statement as fact, of that concerning which the least element of doubt remains. But the real advance of zoological knowledge must not thereby be discredited, for it is due to those who have contributed to it to remember that little more than a generation ago these problems of life seemed wrapped in hopeless obscurity, and the methods of investigation which have led to practically all our present gains, were then but new born, and with every passing year doubts are dispelled,