APPENDIX D 229 



communities, and we have striking evidence that some species 

 of ants, at least, and probably all of them, are actuated largely 

 by knowledge and motives which are acquired, i.e. by reason, 

 and not by inborn mental characters, by instinct. Thus enslaved 

 ants captured as pupae, and educated wholly by their captors, differ 

 markedly from the free members of the species ; they have other 

 knowledge and ways of thinking and acting, and the fact that the 

 slaves in their new homes so readily adapt themselves to the 

 changed environment, so readily exhibit knowledge and ways of 

 thinking and acting, which must be acquired, and cannot possibly 

 be instinctive, for the reason that their ancestry can never have 

 been subjected to the influence of a like environment, proves how 

 great a share reason has in all that is mental in them. And since 

 the slaves clearly acquire mental traits which fit them for their 

 duties as servants, it is not unreasonable to suppose that the 

 slave-holders, in like manner, individually acquire the mental traits 

 which fit them for their functions as masters, i.e., that in them 

 the slave-holding habit is not instinctive, but rational. The lower 

 vertebrata do not tend their young, which, therefore, are hatched 

 highly endowed with instinct, but with very little power of acquir- 

 ing mental characters. Reptiles, having better developed brains, 

 have greater capacities for acquirement than fish ; they can be 

 trained to a much greater extent, can learn much more, and have 

 been known to manifest affection for their masters, in which cases 

 the acquired affection has been so strong as to overcome the in- 

 stinctive dislike. Birds and mammals, like ants, tend their young, 

 which, in proportion to the amount of protection accorded, are 

 born helpless and devoid of instinct, but capable of mental 

 acquirement. Ever as we rise upwards in the scale do we 

 find this increasing protection associated with a growing help- 

 lessness at birth, and a steadily enlarged capacity for acquirement, 

 which finds physical expression in a more and more developed 

 brain, especially of the cerebral portion of it. A partridge at 

 hatching, and a fawn at birth, are able to co-ordinate their 

 muscles to a considerable extent, and have many other instincts. 

 The parrot and the pup are very much more helpless, but their 



