thorns as a defence against apes and serpents. The eggs of the cuckoo, as regards size, colour, and marking, invariably resemble those of the birds in whose nests she lays. Sylvia rufa, for example, lays a white egg with violet spots; Sylvia hippolais, a red one with black spots; Regulus ignicapellus, a cloudy red; but the cuckoo's egg is in each case so deceptive an imitation of its model, that it can hardly be distinguished except by the structure of its shell.

Huber contrived that his bees should be unable to build in their usual instinctive manner, beginning from above and working downwards; on this they began building from below, and again horizontally. The outermost cells that spring from the top of the hive or abut against its sides are not hexagonal, but pentagonal, so as to gain in strength, being attached with one base instead of two sides. In autumn bees lengthen their existing honey cells if these are insufficient, but in the ensuing spring they again shorten them in order to get greater roadway between the combs. When the full combs have become too heavy, they strengthen the walls of the uppermost or bearing cells by thickening them with wax and propolis. If larvae of working bees are introduced into the cells set apart for drones, the working bees will cover these cells with the flat lids usual for this kind of larva, and not with the round ones that are proper for drones. In autumn, as a general rule, bees kill their drones, but they refrain from doing this when they have lost their queen, and keep them to fertilize the young queen, who will be developed from larvae that would otherwise have become working bees. Huber observed that they defend the entrance of their hive against the inroads of the sphinx moth by means of skilful constructions made of wax and propolis. They only introduce propolis when they want it for the

execution of repairs, or for some other special purpose. Spiders and caterpillars also display marvellous dexterity in the repair of their webs if they have been damaged, and this requires powers perfectly distinct from those requisite for the construction of a new one.

The above examples might be multiplied indefinitely, but they are sufficient to establish the fact that instincts are not capacities rolled, as it were, off a reel mechanically, according to an invariable system, but that they adapt themselves most closely to the circumstances of each case and are capable of such great modification and variation that at times they almost appear to cease to be instinctive.

Many will, indeed, ascribe these modifications to conscious deliberation on the part of the animals themselves, and it is impossible to deny that in the case of the more intellectually gifted animals there may be such a thing as a combination of instinctive faculty and conscious reflection. I think, however, the examples already cited are enough to show that often where the normal and the abnormal action springs from the same source, without any complication with conscious deliberation, they are either both instinctive or both deliberative.1 Or is that which prompts the bee to build hexagonal prisms in the middle of her comb something of an actually distinct character from that which impels her to build pentagonal ones at the sides? Are there two separate kinds of thing, one of which induces birds under certain

1 "Indessen glaube ich, dass die angeführten Beispiele zur Genüge beweisen, dass es auch viele Fälle giebt, wo ohne jede Complication mit der bewussten Ueberlegung die gewöhnliche und aussergewöhnliche Handlung aus derselben Quelle stammen, dass sie entweder beide wirklicher Instinct, oder beide Resultate bewusster Ueberlegung sind."-Philosophy of the Unconscious, 3rd ed., p. 76.

circumstances to sit upon their eggs, while another leads them under certain other circumstances to refrain from doing so? And does this hold good also with bees when they at one time kill their brethren without mercy and at another grant them their lives? Or with birds when they construct the kind of nest peculiar to their race, and, again, any special provision which they may think fit under certain circumstances to take? If it is once granted that the normal and the abnormal manifestations of instinct-and they are often incapable of being distinguished-spring from a single source, then the objection that the modification is due to conscious knowledge will be found to be a suicidal one later on, so far as it is directed against instinct generally. It may be sufficient here to point out, in anticipation of remarks that will be found in later chapters, that instinct and the power of organic development involve the same essential principle, though operating under different circumstances-the

two

melting into one another without any definite boundary between them. Here, then, we have conclusive proof that instinct does not depend upon organization of body or brain, but that, more truly, the organization is due to the nature and manner of the instinct.

On the other hand, we must now return to a closer consideration of the conception of a psychical mechanism.1 And here we find that this mechanism, in spite of its explaining so much, is itself so obscure that we can hardly form any idea concerning it. The motive enters the mind by ways of a conscious sensual impres

1 Dagegen haben wir nunmehr unseren Blick noch einmal schärfer auf den Begriff eines psychischen Mechanismus zu richten, und da zeigt sich, dass derselbe, abgesehen davon, wie viel er erklärt, so dunkel ist, dass man sich kaum etwas dabei denken kann."-Philosophy of the Unconscious, 3rd ed., p. 76.

sion; this is the first link of the process; the last link' appears as the conscious motive of an action. Both, however, are entirely unlike, and neither has anything to do with ordinary motivation, which consists exclusively in the desire that springs from a conception either of pleasure or dislike the former prompting to the attainment of any object, the latter to its avoidance. In the case of instinct, pleasure is for the most part a concomitant phenomenon; but it is not so always, as we have already seen, inasmuch as the consummation and highest moral development of instinct displays itself in self-sacrifice.

The true problem, however, lies far deeper than this. For every conception of a pleasure proves that we have experienced this pleasure already. But it follows from this, that when the pleasure was first felt there must have been will present, in the gratification of which will the pleasure consisted; the question, therefore, arises, whence did the will come before the pleasure that would follow on its gratification was known, and before bodily pain, as, for example, of hunger, rendered relief imperative? Yet we may see that even though an animal has grown up apart from any others of its kind, it will yet none the less manifest the instinctive impulses of its race, though experience can have taught it nothing whatever concerning the pleasure that will ensue upon their gratification. As regards instinct, therefore, there must be a causal connection between the motivating sensual conception and the will to perform the instinc

1 "Das Endglied tritt als bewusster Wille zu irgend einer Handlung auf; beide sind aber ganz ungleichartig und haben mit der gewöhnlichen Motivation nichts zu thun, welche ausschliesslich darin besteht, dass die Vorstellung einer Lust oder einer Unlust das Begehren erzeugt, erstere zu erlangen, letztere sich fern zu halten." - Philosophy of the Unconscious, 3rd ed., p. 76.

1

tive action, and the pleasure of the subsequent gratification has nothing to do with the matter. We know by the experience of our own instincts that this causal connection does not lie within our consciousness; therefore, if it is to be a mechanism of any kind, it can only be either an unconscious mechanical induction and metamorphosis of the vibrations of the conceived motive into the vibrations of the conscious action in the brain, or an unconscious spiritual mechanism.

In the first case, it is surely strange that this process should go on unconsciously, though it is so powerful in its effects that the will resulting from it overpowers every other consideration, every other kind of will, and that vibrations of this kind, when set up in the brain, become always consciously perceived; nor is it easy to conceive in what way this metamorphosis can take place so that the constant purpose can be attained under varying circumstances by the resulting will in modes that vary with variation of the special features of each individual case.

But if we take the other alternative, and suppose an unconscious mental mechanism, we cannot legitimately conceive of the process going on in this as other than what prevails in all mental mechanism, namely, than as by way of idea and will. We are, therefore, compelled to imagine a causal connection between the consciously recognized motive and the will to do the instinctive action, through unconscious idea and will; nor do I

1 "Diese causale Verbindung fällt erfahrungsmässig, wie wir von unsern menschlichen Instincten wissen, nicht in's Bewusstsein; folglich kann dieselbe, wenn sie ein Mechanismus sein soll, nur entweder ein nicht in's Bewusstsein fallende mechanische Leitung und Umwandlung der Schwingungen des vorgestellten Motivs in die Schwingungen der gewollten Handlung im Gehirn, oder ein unbewusster geistiger Mechanismus sein."-Philosophy of the Unconscious, 3rd ed., p. 77.