. . . Mr. A. R. Wallace said there was, to his mind, a considerable amount of obscurity about what was really meant by instinct. It included a considerable number of phenomena, some of them mere results of muscular and nervous co-ordination, and in other cases simply the results of observations and experience. Referring to the supposed instinct guiding the migration of birds, he said the present state of facts tended to show that there was no such power at all, but rather led to the belief that this migration was one of the means of getting rid of the enormous surplus of bird population, as it had been proved, especially by the observations promoted by the British Association at lighthouses and Heligoland, that of the vast numbers of birds which sought to pass from one region to another only a small proportion survived.

     Prof. Ray Lankester wished to know whether Mr. Wallace abandoned the supposition of instinct altogether. He thought there were many instances which might be adduced which could not be accounted for on the theory of observation or of having learnt from others, and referred especially to certain habits of the caddisfly in support of his contention. He asked, also, why birds, for example, should go to the west and not to the east in their migration. These things required further investigation, and they must not draw any conclusion from what had been brought before them, as that the phenomena referred to were, if necessary, to be explained by instinct or the reverse.

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      . . . Mr. A. R. Wallace called attention to the fact that the paper was written some 30 years ago, and that since then considerable light had been thrown upon many of the phenomena noted. No doubt if Mr. Darwin had written recently he would have considerably modified his views upon many of them. There was, to his mind, a considerable amount of obscurity about what was really meant by instinct. It included a considerable number of phenomena, some of them mere results of muscular and nervous co-ordination, and in other cases simply the results of observations and experience. Referring to the supposed instinct guiding the migration of birds, he said the present state of facts tended to show that there was no such power at all, but rather led to the belief that this migration was one of the means of getting rid of the enormous surplus of bird population, as it had been proved, especially by the observations promoted by the British Association at lighthouses and Heligoland, that of the vast numbers of birds which sought to pass from one region to another only a small proportion survived. Many other points in the paper were criticized as pointing to imperfect observation. . . .