The coloration of these creatures is very varied: spots of black, or bordered with black upon a more or less tawny ground-colour, is the prevailing pattern. Stripes are also met with, as in the Tiger, but these are usually cross stripes,[271] while in the related Viverridae there are many examples of longitudinal stripes. Finally, many Cats, as for instance the Puma and the Eyra, are "self-coloured"--have, that is to say, a uniform tint. Just as the unstriped Horse sometimes shows traces of the former existence of stripes, so the self-coloured Cats are occasionally spotted when young; this is markedly so in the case of the Puma; while the Lion is spotted as a cub, and in the adult--particularly in the lioness--there are distinct indications of these spots. It is evident, therefore, that there are grounds for regarding a spotted condition to be antecedent, at least in some cases, to a uniform colour. There are divers explanations of these hues and of these changes. It is held by many that the coloration has a relation to the habits of the creature: the spotted Cats, it is pointed out, are largely arboreal; this is eminently so with the Jaguar at any rate; and in an arboreal {393} creature the spots, it is said, give the impression of flecks of sunlight broken up by foliage. On the other hand, the self-coloured Cats of a sandy to earthen hue assimilate in tint with a sandy or stony soil. The stripes of the Tiger, it is thought, approximate to the tall parallel stems of grasses and other plants in the dense cover in which it lives. In favour of these views is undoubtedly the fact that in other mammals and other animals belonging to quite different groups the same four plans of coloration are met with. Spots and cross stripes are found in the Marsupials; the young Tapir is spotted while the adult is self-coloured, and so forth. This last fact, however, serves to illustrate another view which has been put forward in explanation of these characteristic markings of the Felidae. Eimer has come to the conclusion that there is and has been a regular series of steps in the evolution of these markings. The primitive condition was, he thinks, a longitudinally striped one; the stripes then broke up into spots, and the spots rearranged themselves as transverse stripes; the self-coloured Puma and Lion are a final stage in this gradual evolution. In support of this is the fact that spots precede self-coloration in the individual growth of these animals. The exact sequence of these markings is, however, contradicted by Dr. Haacke's observations upon a certain Australian fish which is cross striped when young and longitudinally striped when adult, a precise reversal of what ought to occur on Eimer's view. The Felidae are almost universally distributed with the exception, of course, of Australia and a good deal of the Australian region; the headquarters of the group are undoubtedly in the tropics of the Old World.