326 NATURAL SCIENCE. May, 



transmission." Other writers render the term " instinct " indefinite 

 by including the effects of individual experience. Mr. A. R. Wallace, 

 for example, says-* 1 : " Much of the mystery of instinct arises from 

 the persistent refusal to recognise the agency of imitation, memory, 

 observation, and reason as often forming part of it. Yet there is 

 ample evidence that such agency must be taken into account." But 

 would it not be well, one may ask, so to define instinct as to 

 distinguish it from these agencies ; and to say that the habits or 

 activities of animals are of mixed origin, the term instinct being 

 reserved for particular types of connate activity ? 



7. The Periodicity and Serial Nature of Instinct. — Little need 

 be said on this head, since most writers recognise the facts as, at any 

 rate in many cases, characteristic of instinct. The sexual instincts, 

 nidification, incubation, and migration, exemplify the periodic nature 

 of instinct ; and the fact that this periodicity involves internal as well 

 as external determination suggests the rejection of Professor Bald- 

 win's distinction between impulsive and instinctive ; not because it is 

 logically incorrect, but because there is so much overlap, many 

 instincts involving an impulsive factor. That instincts are very often 

 serial in their nature and involve a chain of activities is also 

 commonly admitted, and is well brought out by Herr Schneider.-* 2 



8. Suggested Scheme of Terminology. — From what has gone 

 before, it will be seen that there is a good deal of diversity of opinion 

 and of definition in the matter of instinct. Let us summarise some 

 of these diversities. 



Instinctive activities are unconscious (Claus), non - mental 

 (Calderwood), incipiently conscious (Spencer), distinguished by the 

 presence of consciousness (Romanes), accompanied by emotions in 

 the mind (Wundt), involve connate ideas and inherited knowledge 

 (Spalding) ; synonymous with impulsive activities (James), to be dis- 

 tinguished from those involving impulse proper (Hoffding, Marshall) ; 

 not yet voluntary (Spencer), no longer voluntary (Lewes), never 

 involuntary (Wundt) ; due to natural selection only (Weismann), to 

 lapsed intelligence (Lewes, Schneider, Wundt), to both (Darwin, 

 Romanes) ; to be distinguished from individually-acquired habits 

 (Darwin, Romanes, Sully, and others), inclusive thereof (Wundt) ; at 

 a minimum in man (Darwin, Romanes), at a maximum in man 

 (James) ; essentially congenital (Romanes), inclusive of individually- 

 acquired modifications through intelligence (Darwin, Romanes, 

 Wallace). 



It is scarcely probable that in the face of such divergence of 

 opinion unanimity is yet within the bounds of reasonable expectation, 

 and the following scheme must be regarded as provisional and 

 suggestive. Certain points must be borne in mind in endeavouring 

 to frame satisfactory and acceptable definitions of the terms 



11 "Darwinism," p. 442. 



u " Der Thierische Wille " e.g., p. 208. 



