216 ANIMAL BEHAVIOUR 



vene, e.g., in type-writing and piano-playing, between the 

 external stimulus and the overt reactions when more than a 

 single reflex is involved. 



There is not at present any convincing evidence that the 

 direct results of habituation can be as such entailed on the off- 

 spring, and there are few available facts in support of the 

 theory once widely held that instinctive predispositions to 

 go through a certain routine are the hereditary results of the 

 habituation of what was originally intelligent. That the 

 instinctive capacities are inborn is certain, but it does not 

 follow that they have been due to ' lapsed intelligence \ At 

 the same time, it is a fact of observation that the individual 

 performance of a piece of instinctive routine may bring with 

 it an increased perfection. 



It is very interesting to find that particular reactions 

 periodically repeated may take such a grip of the individual 

 constitution that they are exhibited even in the absence of 

 the liberating external stimulus. It is probable that this 

 implies, in part at least, that long continuance of external 

 periodicities has established internal rhythms in some im- 

 portant part of the metabolism of the individual creature. 



In the simplest forms of behaviour, which imply little 

 more than a co-ordination of a series of reflexes towards a 

 desired result, there must also be organic registration. This 

 is shown by the simple experiment of putting a starfish on 

 its back, for it learns to right itself more and more quickly 

 as time goes on. Although its effective behaviour is not 

 instinctive, for it has to be learned, nor intelligent, since 

 there are no nerve : ganglia, it improves with practice. 



We shall return to the subject when we come to discuss 

 the evolution of behaviour, but in the meantime we notice 

 the suggestion that it is, metaphorically speaking, part of the 



