xin SOCIAL INSTINCTS 309 



ably hereditary, perfection in the art is acquired by practice. 

 One might, as Schneider says, 2 attribute the opening of fir 

 cones by the woodpecker to get at the seeds inside, to an 

 inherited method of reaction to a certain perception ; but, 

 in point of fact, it appears that the old birds bring the 

 young, first the seed itself, then partly opened cones, and 

 then the complete cones. Thus the method of preparing 

 the family dinner is at least as much a tradition as an 

 instinct. 



Such instances suggest that in the higher instincts, while 

 the ground plan is no doubt determined by heredity, many 

 of its points are grasped by intelligence. Instinct prompts 

 the building of the nest, but intelligence notices a casual 

 defect, and makes it good. There is hereditary impulse to 

 feed, clean, and protect the young, but there is a sufficiently 

 clear understanding of what the young wants at any given 

 moment sufficiently clear to enable a special need to be 

 met by methods not provided for by heredity. Thus, at 

 this stage, pure instinct tends to disappear, or, more strictly, 

 to become suffused with intelligence. Intelligence grows 

 in power of grasping the purposes which instinct sets before 

 the individual, and in carrying them into effect by means 

 suggested by experience or the perception of special 

 circumstances. 



The use of " sentinels," which is widely diffused among 

 birds and mammals, is another practice which, though 

 perhaps more uniform in its working, is very difficult to 

 understand, without allowing a measure of intelligence 

 to eke out habit and instinct. Mr. Cornish (pp. 48, 49) 

 quotes from Mr. St. John a vivid description of the manner 

 in which a flock of wild geese coming to a field of newly 

 sown grain " make numerous circling flights " before 

 alighting, "and the least suspicious object prevents them 

 from pitching." If they do alight they remain motion- 

 less a minute or two with head erect reconnoitring. 

 They then leave a sentry who " either stands on some 

 elevated part of the field, or walks slowly with the 

 rest never, however, venturing to pick up a single grain 



1 Wallace, loc. dt. ; Lloyd Morgan, Habit and Instinct, pp. 234 ff. ; 

 Romanes, M.E.A. pp. 209-212. 2 P. 298. 



