The Descent of Man. 167 



tliat wliicli will not. So, the lowest forms of life sIioav evi- 

 dences of the possession of sensation and memory, and thus 

 have the possibility of the development of mind. The re- 

 sult of the possession of sensation and memory is the 

 capacity for forming a simple judgment. Insects such as 

 the hymenoptera, like bees, wasps and also ants, show a 

 marvellous development of intelligence, and no one doubts 

 that they gained their intelligence in the same way as the 

 higher animals. They have remained as they noAv are 

 many geological ages. The ant and the bee do things with 

 their own kind that man cannot do with his kind. They 

 are practical stirpieulturists, and are more intelligent than 

 many of the vertebrates. The ants have made as great a 

 mark in the animal Avorld as mankind has done. Thus 

 they have called into existence numerous species, genera, 

 and families of other animals that live on them. Among 

 Vertebrata we have families of Batrachia (Cajciliida); of 

 lizards (Amphisbgenidse) ; of snakes (Typhlopidae) ; of birds 

 (Formicariidie) ; and of Mammalia (Myrmecophagidae and 

 (Jrycteropodida:^), six in all, composed of numerous genera 

 and species, Avhicli live exclusively, or nearly so, on ants. 

 Then ants maintain and propagate numerous parasitic spe- 

 cies, mostly of insects. In Europe alone one hundred such 

 species are known. Yet ants do not display the capacity 

 for prompt adaptation to new circumstances so natural to 

 man. Their action is now largely automatic, or fixed in a 

 routine. ]\Ian has a great advantage over the rest of the 

 animal kingdom in possessing a greater power of so-called 

 voluntary choice in determining what he will do. This 

 really means a higher intelligence. 



Sensation, even in its lowest form, is something more 

 than the operation of a merely mechanical energy. It is 

 not analogous, as some have affirmed, to chemical reaction. 

 The tendency of energy in the inorganic world is to dissi- 

 pate. Sensation is profitable to its possessors in enabling 

 them to resist this tendency. The dead products of con- 

 scious action are profitable — as witness the stored-up 

 products of the chalk-cliffs and coal-beds so useful to man. 

 In the combustion of coal we are liberating energy which 

 Avas stored up by vital processes. The action of life has 

 been to build, and not to destroy. 



Sensation is probably a quality of all life, even of \'egeta- 

 ble life in its first beginnings. All life-processes which are 



