Dogs.
Among the canidæ one is able to select a type with whose habits of life we are more familiar than any other, Canis Familiaris, as he is affectionately called, the companion of man his master, and faithful guardian—often unto death. Professor Scott Elliott gives reason to think that the dog was the first animal tamed by man, and that he was descended from some wild jackal-like form, probably crossed by the wolf. The dog is then aptly called by Huxley, the brother of the wolf, who has been changed by the intelligence of man into the guardian of the flock. It seems that in his rudimentary stage of domestication he was an unofficial scavenger among the habitations of neolithic man, as the pariah is in the East to-day, and that little acts of kindness towards his offspring on the part of those early men and women were the first dawnings of a friendship of thousands of years. It is a long story from the slinking jackal to the bloodhound, mastiff, St. Bernard, staghound, collie and terrier of to-day, and one which reflects much credit on both parties to this friendship, just as do those other long friendships between servant and master, of which we still see a few examples. Living with us as he does the dog and his habits of life are an open book: he is then all the better for my humble purpose here. I would refer again to the curious use of the gender which we unconsciously apply to the dog. It is no longer “she,” but “he.” When a dog is looking a little unfriendly how we always try to wheedle him with “Poor old fellow,” and so on, as a matter of course, assuming his masculine character. James Payn pointed out once a little point which proves how good a comrade we have in the dog, when he reminds us of the cautious approach we usually make to a cat, and the “hail-fellow-well-met” tone we adopt towards the dog, rolling him over and using kindly opprobrious terms, such as friends among schoolboys hurl at one another when they are on the best of terms. A fox-terrier is, perhaps, the most human of all the numerous types evolved through the skill of man, and it is a smooth-coated specimen of this variety which I will examine now as to what his hairy coat can tell us of his habits.
Some of the Dog’s Habits.
Fig. 38.—Gluteal region of dog, showing whorls over the tuberosities of the ischia.
His attitudes which bear on this question are all of the passive order. His locomotion is so fitful and different from that of the horse that we shall find on his coat no animal pedometers.
His passive attitudes consist of standing, sitting and lying. He stands little, sits more, and lies for a great part of each day. The standing habit has, of course, no influence upon his hair. In sitting he rests the chief weight of his body on the rounded, bursa-covered surfaces of his tuberosities of the ischium, in which there is nothing peculiar to himself. His fore legs are planted nearly upright on the ground and his hind legs doubled under him or projecting slightly to one or other side, as we saw in the case of the cow. The fore legs are obviously in no way affected as to the direction of the hair in the sitting posture, and the hind legs, being doubled up and subject to the direct downward weight of the body, are also free from the sliding pressure, which we shall see affects the fore limb when the dog lies prone. Thus of the three supports, fore legs, hind legs and tuberosities of the ischium, two are necessarily unaffected in their patterns of hair. The anatomical conditions of his tuberosities are very different in this respect. They are covered with a large slippery bursa just beneath the thick skin, and the slightest movement of this alert and restless animal, even of his head, conveys to this region a small change of position. He is virtually like a sick person on a water or air cushion, and we all know how very small movements of the body are felt in a slight stirring of the supported parts by these. The effect of this is that the hair over these bursæ is seldom at rest from external or extraneous forces, to say nothing of its own imperious constant growth of one inch in two months. In Fig. 38 one sees the hair-stream curving round the buttocks towards the region of these bursæ, and trying to reach the middle line. It meets with so much opposition that the very conditions for producing a reversed area are present and the result is just what one would expect to find. The pattern is formed exactly over the bursæ limited to this area, and it does not expand anywhere because there is no need for it to do so. So when one observes on the surface just below the tail a pattern, often in a black-and-tan terrier marked by a tan patch of hair, one reads the record of the long time spent by the dog in sitting as he meditates on some fresh or past escapade of “A Dog’s Day.”
The statement just made that the hind leg does not share in the effects of pressure is not strictly correct; it applies to the leg properly so called. But the upper part of the thigh exhibits a very clear reversal of hair due to the weight of the body acting here against the streams from the side of the thigh, which are seen endeavouring to make their way to the inner side. They are arrested by a long ridge of hair which marks the obstacle presented by the weight of the body acting here. This completes the story of the way in which sitting affects the hair of the dog, and is shown in Fig. [38].