RELATIONS OF COMPARATIVE PSYCHOLOGY 703 



therein are subject to the psychological order of heredity, so that 

 the controlling influence of the environment is determined by 

 feeling-tone and values for conscious experience. If then we speak 

 of the development of a situation in conformity with the satisfaction 

 it affords, as in accordance with the psychological end, and its 

 development in conformity with the preservation and conservation 

 of the race as in accordance with the biological end, the salient 

 fact is that the two ends are consonant. This has, of course, been 

 fully recognized by evolutionists from Herbert Spencer onwards. 

 I will not here lay stress upon the noteworthy fact, which has not, 

 I think, been sufficiently recognized by the Lamarckian school of 

 evolutionists, that this consonance of biological and psychological 

 end, is admitted to be the outcome of the survival of those in which 

 the consonance obtained, and the elimination of those in which it 

 was absent that is to say is admitted to be dependent on natural 

 selection. I would rather lay stress upon the fact that this con- 

 sonance affords a striking link of continuity between the more dis- 

 tinctively biological and the more distinctively psychological factors 

 of the genetic process. 



The relation between the two has been well brought out in Pro- 

 fessor Groos's discussion of the so-called play of animals. Indeed 

 such play admirably illustrates the twofold influence of heredity; 

 for on the one hand, it is founded on unquestionably instinctive 

 modes of behavior; and on the other hand, it not less obviously 

 appeals to an innate sense of satisfaction. Why do animals begin 

 to play and keep on playing? From the psychological point of view 

 because they like it : from the biological point of view because they 

 thus gain practice and preparation for the serious business of their 

 after-life. But why do they like it? Because under natural selection, 

 those who did not like it, and therefore did not undergo the pre- 

 paratory training and discipline of play, proved unfit for life's 

 sterner struggle, and have been therefore eliminated. I have con- 

 tended that inherited modes of behavior present to consciousness 

 ready-made situations which develop automatically on biological 

 lines, and that the role of environing intelligence is to lead to modi- 

 fications in their redevelopment in accordance with their psycho- 

 logical values. I have also called to remembrance the fact that in 

 the animal world, under normal conditions, these psychological 

 values with their appeal to feeling are consonant with biological 

 values in terms of survival. Throughout the course of mental de- 

 velopment, in the perceptual sphere, there is a constant interaction 

 between the two factors broadly classed under the heads, "instinct" 

 and " intelligence." And it is the province of detailed study to assess 

 at their true value the roles played by these two factors in the par- 

 ticular cases which fall under consideration. A biological survey 



