Racial Preparation 427 
action, which we ourselves require experience to enable us to per- 
form, when performed by an animal, more especially by a very young 
one, without experience, and when performed by many individuals 
in the same way, without their knowing for what purpose it is 
performed, is usually said to be instinctive.” And in the summary 
at the close of the chapter he says!, “I have endeavoured briefly to 
show that the mental qualities of our domestic animals vary, and 
that the variations are inherited. Still more briefly I have attempted 
to show that instincts vary slightly in a state of nature. No one will 
dispute that instincts are of the highest importance to each animal. 
Therefore there is no real difficulty, under changing conditions of life, 
in natural selection accumulating to any extent slight modifications 
of instinct which are in any way useful. In many cases habit or use 
and disuse have probably come into play.” 
Into the details of Darwin’s treatment there is neither space nor 
need to enter. There are some ambiguous passages ; but it may be 
said that for him, as for his followers to-day, instinctive behaviour is 
wholly the result of racial preparation transmitted through organic 
heredity. For the performance of the instinctive act no individual 
preparation under the guidance of personal experience is necessary. 
It is true that Darwin quotes with approval Huber’s saying that 
“a little dose of judgment or reason often comes into play, even with 
animals low in the scale of nature.’ But we may fairly interpret his 
meaning to be that in behaviour, which is commonly called instinctive, 
some element of intelligent guidance is often combined. If this be 
conceded the strictly instinctive performance (or part of the per- 
formance) is the outcome of heredity and due to the direct trans- 
mission of parental or ancestral aptitudes. Hence the instinctive 
response as such depends entirely on how the nervous mechanism 
has been built up through heredity ; while intelligent behaviour, or 
the intelligent factor in behaviour, depends also on how the nervous 
mechanism has been modified and moulded by use during its develop- 
ment and concurrently with the growth of individual experience in 
the customary situations of daily life. Of course it is essential to 
the Darwinian thesis that what Sir E. Ray Lankester has termed 
“educability,” not less than instinct, is hereditary. But it is also 
essential to the understanding of this thesis that the differentiae of 
the hereditary factors should be clearly grasped. 
For Darwin there were two modes of racial preparation, (1) natural 
selection, and (2) the establishment of individually acquired habit. 
He showed that instincts are subject to hereditary variation ; he saw 
that instincts are also subject to modification through acquisition in 
the course of individual life. He believed that not only the variations 
1 Origin of Species (6th edit.), p. 233. 2 Ibid, p. 205, 
