(Figs. 153 and 154). Young mocking-birds will go into spasms at the sight of an owl or a cat, while they pay little attention to a dog or a hen. Monkeys that have never seen a snake show almost hysterical fear at first sight of one, and the same kind of feeling is common to most A monkey was allowed to open a paper bag which

men.

FIG. 153.-Nestlings of the American bittern. Two of a brood of four birds one week old, at which age they showed no fear of man. Photograph by E. H. TABOR, Meridian, N. Y., May 31, 1898. (Permission of Macmillan Company, publishers of Bird-Lore.)

contained a live snake. He was staggered by the sight, but after a while went back and looked in again, to repeat the experience. Each wild animal has its special instinct of resistance or method of keeping off its enemies. The stamping of a sheep, the kicking of a horse, the running in a circle of a hare, and the skulking in a circle of some foxes, are examples of this sort of instinct.

133. Play. The play instinct is developed in numerous animals. To this class belong the wrestlings and mimic fights of young dogs, bear cubs, seal pups, and young beasts generally. Cats and kittens play with mice. Squir

FIG. 154.-Nestlings of the American bittern. The four members of the brood of which two are shown in Fig. 153, two weeks old, when they showed marked fear of man. Photograph by F. M. CHAPMAN, Meridian, N. Y., June 8, 1898. (Permission of Macmillan Company, publishers of Bird-Lore.)

rels play in the trees. Perhaps it is the play impulse which leads the shrike or butcher-bird to impale small birds and beetles on the thorns about its nest, a ghastly kind of ornament that seems to confer satisfaction on the bird itself. The talking of parrots and their imitations of the sounds they hear seem to be of the nature of play. The greater

their superfluous energy the more they will talk. Much of the singing of birds, and the crying, calling, and howling of other animals, are mere play, although singing primarily belongs to the period of reproduction, and other calls and cries result from social instincts or from the instinct to care for the young.

134. Climate.-Climatic instincts are those which arise from the change of seasons. When the winter comes the fur-seal takes its long swim to the southward; the wild geese range themselves in wedge-shaped flocks and fly high and far, calling loudly as they go; the bobolinks straggle away one at a time, flying mostly in the night, and most of the smaller birds in cold countries move away toward the tropics. All these movements spring from the migratory instinct. Another climatic instinct leads the bear to hide in a cave or hollow tree, where he sleeps or hibernates till spring. In some cases the climatic instinct merges in the homing instinct and the instinct of reproduction. When the birds move north in the spring they sing, mate, and build their nests. The fur-seal goes home to rear its young. The bear exchanges its bed for its lair, and its first business after waking is to make ready to rear its young.

135. Environment.-Environmental instincts concern the creature's mode of life. Such are the burrowing instincts of certain rodents, the woodchucks, gophers, and the like. To enumerate the chief phases of such instincts would be difficult, for as all animals are related to their environment, this relation must show itself in characteristic instincts.

136. Courtship.-The instincts of courtship relate chiefly to the male, the female being more or less passive. Among many fishes the male struts before the female, spreading his fins, intensifying his pigmented colors through muscular tension, and in such fashion as he can makes himself the preferred of the female. In the little brooks in spring male minnows can be found with warts on the nose or head,

with crimson pigment on the fins, or blue pigment on the back, or jet-black pigment all over the head, or with varied. combinations of all these. Their instinct is to display all these to the best advantage, even though the conspicuous hues lead to their own destruction. Against this contingency Nature provides a superfluity of males.

Among the birds the male in spring is in very many species provided with an ornamental plumage which he sheds when the breeding season is over. The scarlet, crimson, orange, blue, black, and lustrous colors of birds are commonly seen only on the males in the breeding season, the young males and all males in the fall having the plain brown gray or streaky colors of the female. Among the singing birds it is chiefly the male that sings, and his voice and the instinct to use it are commonly lost when the young are hatched in the nest.

Among polygamous mammals the male is usually much larger than the female, and his courtship is often a struggle with other males for the possession of the female. Among the deer the male, armed with great horns, fight to the death for the possession of the female or for the mastery of the herd. The fur-seal has on an average a family of about thirty-two females (Fig. 71), and for the control of his harem others are ready at all times to dispute the possession. But with monogamous animals like the true or hair seal or the fox, where a male mates with a single female, there is no such discrepancy in size and strength, and the warlike force of the male is spent on outside enemies, not on his own species.

137. Reproduction. The movements of many migratory animals are mainly controlled by the impulse to reproduce. Some pelagic fishes, especially flying-fishes and fishes allied to the mackerel, swim long distances to a region favorable for a deposition of spawn. Some species are known only in the waters they make their breeding homes, the individuals being scattered through the wide seas at

other times. Many fresh-water fishes, as trout, suckers, etc., forsake the large streams in the spring, ascending the small brooks where they can rear their young in greater safety. Still others, known as anadromous fishes, feed and mature in the sea, but ascend the rivers as the impulse of reproduction grows strong. Among such species are the salmon, shad, alewife, sturgeon, and striped bass in American waters. The most noteworthy case of the anadromous instinct is found in the king salmon or quinnat of the Pacific coast. This great fish spawns in November. In the Columbia River it begins running in March and April, spending the whole summer in the ascent of the river without feeding. By autumn the individuals are greatly changed in appearance, discolored, worn, and distorted. On reaching the spawning beds, some of them a thousand miles from the sea, the female deposits her eggs in the gravel of some shallow brook. After they are fertilized both male and female drift tail foremost and helpless down the stream, none of them ever surviving to reach the sea. The same habits are found in other species of salmon of the Pacific, but in most cases the individuals of other species do not start so early or run so far. A few species of fishes, as the eel, reverse this order, feeding in the rivers and brackish creeks, dropping down to the sea to spawn.

The migration of birds has relation to reproduction as well as to changes of weather. As soon as they reach their summer homes, courtship, mating, nest-building, and the care of the young occupy the attention of every species.

138. Care of the young. In the animal kingdom one of the great factors in development has been the care of the young. This feature is a prominent one in the specialization of birds and mammals. When the young are cared for the percentage of loss in the struggle for life is greatly reduced, the number of births necessary to the maintenance of the species is much less, and the opportunities for specialization in other relations of life are much greater.