230 A STUDY IN HEREDITY 



capacity for acquirement is greater in proportion. Highest of all, 

 the human infant is born absolutely helpless. It is unable to 

 co-ordinate all but a very few groups of muscles ; its instincts are 

 reduced to a minimum ; it cannot even seek the breast ; but it is 

 protected with prolonged and tender care, under which its vast 

 powers of acquirement come into play. 



Instincts, therefore, have undergone great retrogression in the 

 higher types, but amid this general retrogression three instincts at 

 least, have undergone evolution : (i) the parental instinct to pro- 

 tect the offspring ; (2) the parental instinct to impart to the off- 

 spring the acquired knowledge which subserved the parents' 

 survival; and (3) the instinct which impels the offspring to 

 imitate the parent, and so acquire the physical and mental traits, 

 the traditional knowledge and ways of thinking and acting, which 

 the latter acquired. This subject is a very interesting one, but 

 my space is limited, and therefore I will not dilate upon it, but 

 content myself by instancing such familiar examples as the hen, 

 the cat, and the human being in proof of my statements. Each 

 of these animals teaches its young in different ways, and the 

 instinct of the young causes it to imitate the parent, and sport in 

 such a manner as to develop {i.e. favour the acquirement of) the 

 physical and mental characters which conduce to the survival of 

 the individual and the race. If it be doubted that animals lower 

 than man have traditional knowledge, which is handed from 

 generation to generation, I have only to instance the parrots of 

 New Zealand, which have recently acquired the habit of sheep- 

 eating, and the change which soon occurs in the demeanour of 

 the higher animals towards man when he first enters a land where 

 he was previously unknown, e.g. the Galapagos Islands. In such 

 lands, lower animals (insects, for instance) if they exhibit alarm 

 on his first appearance, show no increase of it in subsequent 

 generations. 



Some of this traditional knowledge, especially when it is of 

 a kind greatly to favour survival, is doubtless of great antiquity. 

 Of such a nature, if I am right in regarding it as an acquirement, 

 must be the slave-making habit of certain ants, since their very 



