INADEQUACY OF NATUEAL SELECTION, ETC. C67 



The other remaining point concerns the vexed question of 

 panmixia. Confirming the statement of Dr. Romanes, Professor 

 Weismann says that I have misunderstood him. Already [Con- 

 temporary Review^ May, 1893, p. 758, and Reprint, p. 66) I have 

 quoted passages which appeared to justify my interpretation, 

 arrived at after much seeking.* Already, too, in this review 

 (July, 1893, p. 54) I have said why I did not hit upon the inter- 

 pretation now said to be the true one : I never supposed that any 

 one would assume, without assigned cause, that (apart from the 

 excluded influence of disuse) the minus variations of a disused 

 organ are greater than the plus variations. This was a tacit 

 challenge to produce reasons for the assumption. Professor 

 Weismann does not accept the challenge, but simply says : — " In 

 my opinion all organs are maintained at the height of their de- 

 velopment only through uninterrupted selection" (p. 332): in 

 the absence of which they decline. Now it is doubtless true that 

 as a naturalist he may claim for his " opinion " a relatively great 

 weight. Still, in pursuance of the methods of science, it seems 

 to me that something more than an opinion is required as the 

 basis of a far-reaching theory. f 



* To save space and exclude needless complication I have omitted these 

 passages from the preceding divisions of this appendix. 



f Though Professor Weismann does not take up the challenge, Dr. 

 Romanes does. He says : — " When selection is withdrawn there will be no 

 excessive pliis variations, because so long as selection was present xhe 

 efficiency of the organ was maintained at its highest level : it was only the 

 mimis variations which were then eliminated" {Contentforary Revieio, p. 611). 

 In the first place, it seems to me that the phrases used in this sentence beg 

 the question. It says that " the efficiency of the organ was maintained at 

 its highest level " ; which implies that the highest level (tacitly identified with 

 the greatest size) is the best and that the tendency is to fall below it. This 

 is the very thing I ask proof of. Suppose I invert the idea and say that 

 the organ is maintained at its right size by natural selection, because this 

 prevents increase beyond the size which is best for the organism. Every 

 organ should be in due proportion, and the welfare of the creature as a whole 

 is interfered with by excess as well as by defect. It may be directly 

 interfered with — as for instance by too big an eyelid; and it maybe indi- 

 rectly interfered with, where the organ is large, by needless weight and cost 

 of nutrition. In the second place the question which here concerns us is not 

 what natural selection will do with variations. We are concerned with the 

 previous question — What variations will arise ? An organ varies in all 

 ways ; and, unless reason to the contrary is shown, the assumption must be 

 that variations in the direction of increase are as frequent and as great as 

 those in the direction of decrease. Take the case of the tongue. Certainly 

 there are tongues inconveniently large, nnd probably tongues inconveniently 

 small. What reason have we for assuming that the inconveniently small 

 tongues occur more frequently than the inconveniently large ones ? None 

 that I can see. Dr. Romanes has not shown that when natural selection 

 ceases to act on an organ the minus variations in each new generation will 

 exceed the plus variations. But if they are equal the alleged process of pan- 

 mixia has no place. 



