MIND IN EVOLUTION 533 



— the recurrence of the nauseous taste in sensory presenta- 

 tion. It is this prevention which renders p re-awareness 

 effective in the guidance of behaviour." 



Now, if this view, so clearly expressed by one of the 

 founders of comparative psychology, be correct, we get two 

 flashes of light on the problem of the evolution of ' mind '. 

 While no suggestion can be offered as to the first emergence 

 of the psychical factor — say the pre-awareness of meaning 

 within a sphere of interest — we may find a pre-condition of 

 it in the physiological capacity of registration and retention 

 which has been recognised as one of the characteristics of 

 organisms. And secondly, in the minute structure of the 

 brain (notably the cerebral cortex) of higher animals there 

 is what may be called an appropriate anatomical basis. 

 That is to say, there is a ^ loop-line ' system, in which in- 

 hibiting or controlling cells intervene between the receptive 

 or sensory centres receiving sense-impressions and the effec- 

 tor or motor centres commanding action. As Prof. Lloyd 

 Morgan tersely puts it, ^' We are now in a position to 

 characterise our a&c-process as that of loop-lines whereon 

 pre-aw^areness, prospective meaning, or prevision of ends, 

 intervenes between the sensory presentation and the re- 

 sponse " (1915, p. 12). 



Very suggestive of mentality are some of the variations 

 in play-instincts as exhibited by kittens, puppies, kids, lambs, 

 and the like. Mr. Hamerton describes the diversity of games 

 exhibited by his young goats, one succeeding another when 

 a new suggestion was made. A psychological element is 

 surely hinted at in cases which seem to the observer like 

 sham-hunts or sham-fights, but it is not the old-established 

 forms of play that seem to us most significant, for they are 

 instinctive. We see more interest in novelties. Thus Dr. 



