probably the most forlorn and abject creature to be seen on the face of the earth is a masterless dog. slouching and slinking along, cringing to every human being it chances to meet, running away with its tail between its legs from smaller dogs whom under other circumstances it would accost with a gruff who-the-dickens-are-you sort of growl,—it forms the very picture of utter humiliation and self-abasement. grip and i have just come across such a lost specimen of stray doghood, trying to find his way back to his home across the fields—i fancy he belongs to a travelling show which left the village yesterday—and it is quite refreshing to watch the air of superior wisdom and calm but mute compassionateness with which grip casts his eye sidelong upon that wretched masterless vagrant, and passes him by without even a nod. he looks up to me complacently as he trots along by my side, and seems to say with his eye, 'poor fellow! he's lost his master, you know—careless dog that he is!' i believe the lesson has had a good moral effect upon grip's own conduct, too; for he has now spent ten whole minutes well within my sight, and has resisted the most tempting solicitations to ratting and rabbiting held out by half-a-dozen holes and burrows in the hedge-wall as we go along.

this total dependence of dogs upon a master is a very interesting example of the growth of inherited instincts. the original dog, who was a wolf or something very like it, could not have had any such artificial feeling. he was an independent, self-reliant animal, quite well able to look after himself on the boundless plains of central europe or high asia. but at least as early as the days of the danish shell-mounds, perhaps thousands of years earlier, man had learned to tame the dog and to employ him as a friend or servant for his own purposes. those dogs which best served the ends of man were preserved and increased; those which followed too much their own original instincts were destroyed or at least discouraged. the savage hunter would be very apt to fling his stone axe at the skull of a hound which tried to eat the game he had brought down with his flint-tipped arrow, instead of retrieving it: he would be most likely to keep carefully and feed well on the refuse of his own meals the hound which aided him most in surprising, killing, and securing his quarry. thus there sprang up between man and the dog a mutual and ever increasing sympathy which on the part of the dependent creature has at last become organised into an inherited instinct. if we could only thread the labyrinth of a dog's brain, we should find somewhere in it a group of correlated nerve-connections answering to this universal habit of his race; and the group in question would be quite without any analogous mechanism in the brain of the ancestral wolf. as truly as the wing of the bird is adapted to its congenital instinct of flying, as truly as the nervous system of the bee is adapted to its congenital instinct of honeycomb building, just so truly is the brain of the dog adapted to its now congenital instinct of following and obeying a master. the habit of attaching itself to a particular human being is nowadays engrained in the nerves of the modern dog just as really, though not quite so deeply, as the habit of running or biting is engrained in its bones and muscles. every dog is born into the world with a certain inherited structure of limbs, sense-organs, and brain: and this inherited structure governs all its future actions, both bodily and mental. it seeks a master because it is endowed with master-seeking brain organs; it is dissatisfied until it finds one, because its native functions can have free play in no other way. among a few dogs, like those of constantinople, the instinct may have died out by disuse, as the eyes of cave animals have atrophied for want of light; but when a dog has once been brought up from puppyhood under a master, the instinct is fully and freely developed, and the masterless condition is thenceforth for him a thwarting and disappointing of all his natural feelings and affections.

not only have dogs as a class acquired a special instinct with regard to humanity generally, but particular breeds of dogs have acquired particular instincts with regard to certain individual acts. nobody doubts that the muscles of a greyhound are specially correlated to the acts of running and leaping; or that the muscles of a bull-dog are specially correlated to the act of fighting. the whole external form of these creatures has been modified by man's selective action for a deliberate purpose: we breed, as we say, from the dog with the best points. but besides being able to modify the visible and outer structure of the animal, we are also able to modify, by indirect indications, the hidden and inner structure of the brain. we choose the best ratter among our terriers, the best pointer, retriever, or setter among other breeds, to become the parents of our future stock. we thus half unconsciously select particular types of nervous system in preference to others. once upon a time we used even to rear a race of dogs with a strange instinct for turning the spit in our kitchens; and to this day the cubans rear blood-hounds with a natural taste for hunting down the trail of runaway negroes. now, everybody knows that you cannot teach one sort of dog the kind of tricks which come by instinct to a different sort. no amount of instruction will induce a well-bred terrier to retrieve your handkerchief: he insists upon worrying it instead. so no amount of instruction will induce a well-bred retriever to worry a rat: he brings it gingerly to your feet, as if it was a dead partridge. the reason is obvious, because no one would breed from a retriever which worried or from a terrier which treated its natural prey as if it were a stick. thus the brain of each kind is hereditarily supplied with certain nervous connections wanting in the brain of other kinds. we need no more doubt the reality of the material distinction in the brain than we need doubt it in the limbs and jaws of the greyhound and the bull-dog. those who have watched closely the different races of men can hardly hesitate to believe that something analogous exists in our own case. while the highest types are, as mr. herbert spencer well puts it, to some extent 'organically moral' and structurally intelligent, the lowest types are congenitally deficient. a european child learns to read almost by nature (for dogberry was essentially right after all), while a negro child learns to read by painful personal experience. and savages brought to europe and 'civilised' for years often return at last with joy to their native home, cast off their clothes and their outer veneering, and take once more to the only life for which their nervous organisation naturally fits them. 'what is bred in the bone,' says the wise old proverb, 'will out in the blood.'