Organic Selection as Stcpplementary 137 



plex instincts ; and however these instincts may have been 

 acquired, they may yet be cited to show the sort of crea- 

 tures which the free operation of use-inheritance would 

 produce. Yet just this state of things would again militate 

 against continued use-inheritance, as a general principle 

 of evolution ; for as instinct increases, ability to learn 

 decreases, and so each generation would have less acquisi- 

 tion to hand on by heredity. So use-inheritance would 

 very soon run itself out. Further, (3) the main criticism 

 of the principle of natural selection cited above from the 

 paleontologists, i.e., that from 'non-useful characters,' is 

 not met by use-inheritance ; since the lines of evolution 

 in question are frequently, as in the case of teeth and 

 bony structures, in characters which in the early stages of 

 their appearance are not modified, in the direction in ques- 

 tion, by the use of them by the creatures which have them. 

 And, finally, (4) if it can be shown that natural selection, 

 which all admit to be in operation in any case, can be 

 supplemented by any principle which will meet these ob- 

 jections better than that of use-inheritance, then such a 

 principle may be considered in some degree a direct sub- 

 stitute for the Lamarckian factor. 



§ 2. Orga7itc Selection as a Sttpplenientary Principle 



There is another principle at work whose operation is 

 directly supplementary to natural selection — the principle 

 already described above under the name of Organic 



Selection. 



Put very generally, this principle may be stated as fol- 

 lows : acquired characters, or modifications, or individual 

 adaptations, —all that we are familiar with in the earlier 



