It

remain unmodified throughout life. The chick, however, or the imago insect, is something more than this. It affords evidence of the accommodation of behaviour to varying circumstances. so acts as to lead us to infer that there are centres of intelligent control through the action of which the automatic behaviour can be modified in accordance with the results of experience. When, for example, a young chick walks towards and pecks at a lady-bird, the like of which he has never before seen, the behaviour may be purely instinctive; and so, too, when he similarly seizes a wasplarva.. But when, after a few trials, the chick leaves lady-birds unmolested while he seizes wasp-larvæ with increased energy, he affords evidence of selection based on individual experience. And such selection implies intelligence in almost its simplest expression. We may say, therefore, that, whereas instinctive behaviour is prior to individual experience, intelligent behaviour is the outcome and product of such experience. This distinction is presumably clear enough; and it is one that is based on the facts of observation. But we must not fail to notice that, though the logical distinction is quite clear, the acquired modifications of behaviour, which we speak of as intelligence, presuppose congenital [¿.e. inherited] modes of response which are guided to finer issues. We may say then, that where these congenital modes of response take the form of instinctive behaviour, there is supplied a general plan of action which intelligence particularizes in such a manner as to produce accommodation to the conditions of existence." The quotation just given implies, what is no doubt true, that in the course of mental evolution Instinct does not become Intelligence, but is gradually replaced by it, i.e. inherited specialized behaviour is replaced more or less by self-specialized behaviour. The larger the amount of such replacement the greater the intelligence. And this enables us to understand the peculiar helplessness of the young of higher Mammals, especially those of our own species. The complex instincts of lower forms have been lost, and it takes. a long time to learn how to act intelligently. The remark does not apply to all helpless young, for in some of these, e.g. in nestling birds, such instincts are only deferred. The influence of strongly-developed parental affection is noticeable in both cases.

To interpret the action of animals with any likelihood of accuracy it is necessary to avoid two extreme views of opposite kind. One of these ascribes almost human attributes to even the

lowest animals; it is a case of interpreting the observed in terms of the observer. The other and older view regards Man as the only intelligent animal, all the others being simply living machines worked by Instinct and Reflex Action. There has been in the past a great dearth of patient unbiassed observation on living animals, but the number of competent investigators is now fortunately increasing, and the results already obtained clearly point to the conclusion that extreme opinions in either direction are inadmissible.

The difference between Instinct and Intelligence may also be realized by taking some metaphorical illustration. Let us then compare the successful adjustments of an animal to its environment to the effective shots of a rifleman aiming at a series of targets. And let us also suppose that a certain minimum score is necessary for the maintenance of a bare existence, while marriage is only permitted as the reward of a good score. The shooting of such a rifleman would be comparable to the actions of an animal actuated by pure Instinct, if he were provided with a series of loaded rifles previously sighted and adjusted in such a way that he would merely have to press the triggers to mechanically secure a large number of points-a sort of "you-press-the-button-andwe-do-the-rest " arrangement. If the targets remained fixed the privileges attached to success would be easily secured. But the actions of life have to bring about adjustments to surroundings which are constantly altering, and this may be represented in the illustration by substituting moving targets for stationary ones. The purely "instinctive rifleman" would do pretty well if his targets moved but slightly, though bull's-eyes would be infrequent, and his total would be smaller. But with increasing movement the percentage of hits would dwindle till first of all the prize of matrimony would be denied him, and finally the score would be so small that even bare existence would not be permitted.

Our illustration can easily be modified to represent the gradual replacement of Instinct by Intelligence. By endowing our imaginary rifleman with increasing capacity to adjust his rifles, so as to secure a reasonable score with shifting targets, we make his shooting more and more intelligent, less and less instinctive. And were he simply given the loaded rifles, and left to learn the art of marksmanship for himself, success would require a high degree of intelligence. The loaded rifles would represent the gift of inheri

YOUNG ORANG-UTANS (Simia satyrus

The Orang-utan, a man-like ape native to Sumatra and Borneo, is characterized by the great relative length of its arms, a peculiarity associated with purely arboreal habits. The long hair is of a reddish colour. Orangs are undoubtedly very intelligent, and the rounded intellectual-looking forehead gives a very human appearance. The mental powers of the Gorilla and Chimpanzee, however, are more considerable, though the powerful brow-ridges which these forms possess greatly detract from their personal appearance.

The Orang builds a kind of stick-nest in the fork of a tree as a temporary shelter, from which it does not sally forth to feed until the day is well advanced. Small family parties are commonly found associated together, though the male appears to lead a solitary life during a large part of the year. The young are as helpless as those of the human species, and those which have been brought up in captivity present many similar traits. Their wants are expressed by loud lamentations, and they protest loudly if their food is not to their taste. They also greatly appreciate being nursed and "cuddled". Unlike human infants, however, they are eager to be washed and combed.