ORGAXIC EVOLXmON— MENTAL 137 



species of insects, e.g. ants. Often, when the nervous 

 systems appear precisely similar, we find that the 

 mental traits as manifested in the actions of the 

 animals diflfer vastly. Changes in nervous tissue seem 

 magnified a thousandfold when examined through 

 their psychical concomitants. But however obscure 

 and difficult the subject, two facts may be made out : 

 (1) Thai acquired psychical changes are nec^r transmitted, 

 and (2) that, just as regards their corpm-al structures, so 

 as regards their nuntal trails, the action of Kaiural 

 Selection has leen to develop in higher animals an 

 immense poiDcr of varying, of individuaMy acquiring 

 variations, icherdjy the organism is hrougM into completer 

 harm^my iciih its complex environment. 



In animals low in the scale, such as the ccelenterates, 

 almost all the reactions to stimulation from the environ- 

 ment are of the kind known as reflex. la them 

 Natural Selection has brought about the evolution of 

 particular reactions, whereby particular and generally 

 oft-recurring events in the simple environment are pro- 

 Added against ; the power of making these appropriate 

 responses to particular stimuli being obviously inborn 

 and transmissible. Higher in the scale occurs that 

 kind of response to stimulation which is known as 

 Instinct, and which Mr. Spencer has defined as " com- 

 pound reflex action," but which Professor Romanes 

 rightly insists is something more — ^is action into which 

 has been imported the element of consciousness. 



It may be defined as " the fa/euMy which is concerned 

 in the conscious adaption of means to ends," hy virtue of 

 inborn iiiherited knowledge and ways of thinldng and 

 acting. For example, the young alligator or the young 

 turtle instinctively seek the water on emerging fix)m 

 the egg, i. c. they seek it by virtue of their inborn and 

 inherited knowledge and ways of thinking and acting. 

 Instinct also is clearlv transmissible. 



