i66 INSECTS AND HEREDITY 



nerve-mcchanisnis of instinct arc transmitted, and owe 

 their inferiority as compared with the results of education 

 to the very fact that they are not acquired b)- the indi- 

 vidual in relation to his particular needs, but have arisen 

 by selection of conorenital variation in a long series of 

 preceding generations. 



* To a larj/e extent the two series of brain-mechanisms, 

 the "instinctive " and the " individuall\- acquired", are in 

 opposition to one another. Congenital brain-mechanisms 

 may prevent the education of the brain and the develop- 

 ment of new mechanisms specially fitted to the special 

 conditions of life. To the educable animal — the less there 

 is of specialised mechanism transmitted by heredity, 

 the better. The loss of instinct is what permits and 

 necessitates the education of the receptive brain. 



' We are thus led to [the] view that it is hardly possible 

 for a theory to be further froni the truth than that 

 espoused by George H. Lewes and adopted b)- George 

 Romanes, namely that instincts are due to *' lapsed " 

 intelligence. The fact is that there is no community 

 between the mechanisms of instinct and the mechanisms 

 of intelligence, and that the latter are later in the history 

 of the develo^jment of the brain than the former, and can 

 only develop in proportion as the former become feeble 

 and defective.' ^ 



The bear I H!^ of hiscct Warnini:; mid J\Iii)ictic Colours 

 upon tJu supposed Hereditary Transmission of Experience 

 by tJieir J \'rtebrate lineniies. 



Adaptations which facilitate the education of entomo- 

 phagous vertebrates are so perfect and so wide-spread 

 in insects that they constitute a large body of indirect 

 evidence in favour of the non-transmissi(Mi by heredity of 

 the results of experience. Fritz Miillcr. in his celebrated 

 theory of mimicry, suggested that the object of the likeness 

 between the warning colours of specially-protected species 

 was to reduce the danger from the attacks of young and 

 inexperienced enemies. This is all the more interesting 



* From the Jubilee Volume of the Soc. dc Biol.^ Paris, 1899. 

 Reprinted in Nature, vol. Ixi, 1900, pp. 624-5. 



