fold gradations according as in each the cerebral or the ganglion system is preponderatingly developed. Just because the instinctive action and the ingenious contrivances of insects are principally directed from the ganglion system, if we regard them as proceeding from the brain alone, and wish to explain them accordingly, we fall into absurdities, because we then apply a false key. The same circumstance, however, imparts to their action a remarkable likeness to that of somnambulists, which indeed is also explained as arising from the fact that, instead of the brain, the sympathetic nerve has undertaken the conduct of the outward actions also; insects are accordingly, to a certain extent, natural somnambulists. Things which we cannot get at directly we must make comprehensible to ourselves by means of an analogy. What has just been referred to will accomplish this in a high degree when assisted by the fact that in Kieser's "Tellurismus" (vol. ii. p. 250) a case is mentioned "in which the command of the mesmerist to the somnambulist to perform a definite action in a waking state was carried out by him when he awoke, without remembering the command." Thus it was as if he must perform that action without rightly knowing why. Certainly this has the greatest resemblance to what goes on in the case of mechanical instincts in insects. The young spider feels that it must spin its web, although it neither knows nor understands the aim of it. We are also reminded here of the daemon of Socrates, on account of which he had the feeling that he must leave undone some action expected of him, or lying near him, without knowing why – for his prophetic dream about it was forgotten. We have in our own day quite well-authenticated cases analogous to this; therefore I only briefly call these to mind. One had taken his passage on a ship, but when it was about to sail he positively would not go on board without being conscious of a reason; – the ship went down. Another goes with companions to a powder magazine; when he
