INSTINCT AND KEASON. 135 



the form and size of their cells to the particular places or 

 circumstances of their work' (Macaulay). In many other 

 ways bees abandon routine, make deviations from custom, 

 vary their operations with emergency. 



Again, the manners and customs of the same species of 

 ant differ according to its residence in England, the south 

 of France, or India. 



Instincts may be abrogated or lost in consequence of 

 changed conditions of life. Thus domesticated and captive 

 animals that are kindly dealt with by man, and that are sen- 

 sible of the advantages involved in their changed mode of life, 

 appear frequently to lose the instinct of liberty or freedom, 

 in so far as no advantage is taken of the power or opportu- 

 nities of flight or escape. In other circumstances instincts 

 are commonly lost when they are not required : they lapse 

 under disuse. But not always, for there is sometimes a use- 

 less and even a troublesome retention of the old instincts 

 for instance, in the captive beaver. There is frequently a 

 loss of one or more, or all, the natural instincts in various 

 kinds of disease, mental or bodily. 



Just as old instincts lapse where they are not required, 

 new ones are called into existence, or are developed, where 

 they are needed ; and these new or acquired instincts, it is 

 important to bear in mind, are as transmissible hereditarily 

 as the old ones. Nor is it less interesting to note that new 

 instincts may be and are developed, if not created, ly man. 

 As an instance of the natural acquisition of a new instinct 

 in the wild state may be cited the development, since man's 

 settlement, of a flesh-eating propensity in the fruit-feeding 

 ' kea ' of New Zealand, a forest bird ; whereas illustrations 

 of the new instincts developed, directly or indirectly, by 

 man are to be found in those which appear in domesticated 

 animals. 



It does not follow, however, that all instincts described 

 as new appearing for the first time in an individual or spe- 

 cies are so in reality, have been created where or when they 

 did not previously exist. Many of them may have been 

 merely latent or dormant, waiting to be developed to be 

 rendered conspicuous or operative by necessity or by favour- 



