inclined to go with the other chicks, but still ignored the existence of the hen. The natural instinctive tendency seems to be from the first to nestle under anything; and there is the hen provided by nature for the purpose. By experience the chicks grow accustomed to her fussy ways, as they grow accustomed to the ways of such a foster-parent as the writer of these pages. Still, though there is, apparently, no instinctive knowledge of the hen as their natural protector, and though I have seen no observable response to the clucking sound, this must not be taken as necessarily implying that there is no instinctive response to any of her modes of behaviour. There is such a response to her pecking on the ground; there is probably such a response to her danger-note; and there may be many other such instinctive modes of behaviour related to her actions. How far they extend can only be ascertained by patient observation; and such responsive behaviour need not imply any instinctive knowledge begotten of inherited experience. We may now summarize some of the general conclusions which may be drawn from observations of instinctive behaviour in young birds. 1. That which is inherited is essentially a motor response or train of such responses. Mr. Herbert Spencer’s description of instinct as compound reflex action is thus justified. 2. These often show very accurate and nicely-adjusted hereditary co-ordinations. 3. They are evoked by stimuli, the general type of which is fairly definite, and may in some cases be in response to particular objects. 4. They are also generally shown under conditions which lead us to infer the presence of an internal factor, emotional or other. 5. There does not seem to be any evidence of inherited knowledge or experience. IV.--THE CONSCIOUS ASPECT OF INSTINCTIVE BEHAVIOUR In our definition of instinctive behaviour all positive reference to the presence of conscious states was omitted. By some writers, however, the fact that it is accompanied by consciousness is regarded as a distinguishing feature of instinct. Romanes introduced his definition with the words:[38] “Instinct is reflex action into which there is imported the element of consciousness.” And he emphasized the conscious aspect when he said: “The term comprises all those _faculties of mind_ which are concerned with conscious and adaptive action, antecedent to individual experience.” Professor Wundt also lays some stress on the conscious accompaniments of instinctive activities which, he says,[39] “differ from the reflexes proper in this, that they are accompanied by emotions in the mind, and that their performance is regulated by these emotions.” The definitions of other writers express or imply the presence of consciousness in differing modes and degrees, culminating in the hypothesis of inherited knowledge. Douglas Spalding, for example, said[40] that “animals can forget the instinctive knowledge which they never learned!”