134 Mr, Oeorge J. Romanes [Feb. 8, 



is an important factor in the process ; but it neither supposes that it 

 is the only factor, nor even that in the case of numberless instincts 

 it has had anything at all to do with their formation. Take, for 

 example, the instinct of wildness, or of hereditary fear as directed 

 towards any particular enemy — say man. It has been the experience 

 of travellers w^ho have first visited oceanic islands without human 

 inhabitants, and previously unvisited by man, that the animals are 

 destitute of any fear of man. Under such circumstances the birds 

 have been known to alight on the heads and shoulders of the new- 

 comers, and wolves to come and eat meat held in one hand while a 

 knife was held ready to slay them with the other. But this primitive 

 fearlessness of man gradually passes into an hereditary instinct of 

 wildness, as the special experiences of man's proclivities accumulate ; 

 and as this instinct is of too rapid a growth to admit of our attributing 

 it to natural selection (not one per cent, of the animals having been 

 destroyed before the instinct is developed), we can only attribute itis 

 growth to the effects of inherited observation. In other words, just 

 as in the lifetime of the individual, adjustive actions which were 

 originally intelligent may by frequent repetition become automatic, 

 so in the lifetime of the species, actions originally intelligent may, 

 by frequent repetition and heredity, so write their effects on the 

 nervous system that the latter is prepared, even before individual ex- 

 perience, to perform adjustive actions mechanically which, in previous 

 generations, were performed intelligently. This mode of origin of 

 instincts has been called by Mr. Lewes the " lapsing of intelligence," 

 and it was fully recognised by Mr. Darwin as a factor in the formation 

 of instinct. 



The Darwinian theory of instinct, then, attributes the evolution 

 of instincts to these two causes acting either singly or in combination 

 — natural selection and lapsing intelligence. I shall now proceed to 

 adduce some of the more important facts and considerations which, 

 to the best of my judgment, support this theory, and show it to be 

 by far the most comprehensive and satisfactory explanation of the 

 phenomena which has hitherto been propounded. 



That many instincts must have owed their origin and develop- 

 ment to natural selection exclusively is, I think, rendered evident by 

 the following general considerations : — 



(1) Considering the great importance of instincts to species, we 

 are prepared to expect that they must be in large part subject to the 

 influence of natural selection. (2) Many instinctive actions are per- 

 formed by animals too low in the scale to admit of our supposing 

 that the adjustments which are now instinctive can ever have been 

 intelligent. (3) Among the higher animals instinctive actions are 

 performed at an age before intelligence, or the power of learning by 

 individual experience, has begun to assert itself. (4) Many instincts, 

 as we now find them, are of a kind which, although performed by in- 

 telligent animals at a matured age, yet can obviously never have been 

 originated by intelligent observation. Take, for instance, the instinct 



