318 PROBLEMS OF HUMAN EVOLUTION 



of a previous occasion. Give it the same food and it will take 

 it or reject it as before. We do not call this memory, because 

 there is no indirect setting of brain centres to work. Never- 

 theless it is of the nature of memory. If we once recognise 

 that when we recollect a thing, it is because something reminds 

 us of it, the fact becomes clear. A knot in a pocket handker- 

 chief through association makes us remember, say, a letter due 

 to a friend. A "warning to cyclists" may recall a bad smash. 

 There is somehow a reinstatement of a stimulus, and this takes 

 place equally in a protozoon. The difference lies in this that 

 with a complicated brain machinery and a variety of means of 

 communication with the outer world, there are many ways in 

 which the reinstatement may take place. Under these circum- 

 stances we have what we call memory. 



In the lowest brain there is raw material from which very 

 noble things can be manufactured. But if we try to trace the 

 process of manufacture, there are great gulfs which it is difficult 

 to bridge. There is the difficulty, for instance, of abstract ideas. 

 From what rudiment was evolved the power of conceiving 

 roundness, for example, apart from a particular round thing ? 

 And are any of the lower animals capable of even a glimmer of 

 an abstract idea ? These are questions which it is very easy 

 to ask and very difficult to answer. For if it is a hard task to 

 trace the course of evolution with anatomy to help us, it is a 

 hundred times as hard when from the conduct of, say, an 

 elephant, we have to infer his thoughts. 



Though I assume that the highest faculties that men have are 

 found in rudimentary form in the lower animals, I do not wish 

 in any way to depreciate the greatness of man's intellect his 

 power of concentrating his attention, of imitating and learning, 

 his power of abstract thought, his originality. He is a being 

 of infinite versatility who meets the buffets of circumstances with 

 ever new shifts and contrivances, and not only this, but he 

 probes the universe, learns its laws, and philosophises on the 

 thousand facts that he discovers. 



" What a piece of work is man ! how noble in reason ! 

 how infinite in faculty ! In form and moving how express and 



