INADEQUACY OF NATURAL SELECTION, ETC. G49 



Between Dr. Romanes and myself the first difference concerns 

 tlie interpretation of " Panmixia." Clearer conceptions of these 

 matters would be reached if, instead of thinking in abstract terms, 

 the physiological processes concerned were brought into the fore- 

 ground. Beyond the production of changes in the sizes of part3 

 by the selection of fortuitously-arising variations, I can see but 

 one other cause for the production of them — the competition 

 among the parts for nutriment. This has the effect that active 

 parts are well-supplied and grow, while inactive parts are ill- 

 supplied and dwindle.* This competition is the cause of 

 " economy of growth " ; this is the cause of decrease from disuse ; 

 and this is the only conceivable cause of that decrease which Dr. 

 Romanes contends follows the cessation of selection. The three 

 things are aspects of the same thing. And now, before leaving 

 this question, let me remark on the strange proposition which 

 has to be defended by those who deny the dwindling of organs 

 from disuse. Their proposition amounts to this : — that for a 

 hundred generations an inactive organ may be partially denuded 

 of blood all through life, and yet in the hundredth generation 

 will be produced of just the same size as in the first ! 



There is one other passage in Dr. Romanes' criticism — that 

 concerning the influence of a previous sire on progeny — which 

 calls for comment. He sets down what he supposes Weismann 

 will say in response to my argument. " First, he may question 

 the fact." Well, after the additional evidence given above, I 

 think he is not likely to do that ; unless, indeed, it be that along 

 with readiness to base conclusions on things " it is easy to 

 imagine " there goes reluctance to accept testimony which it is 

  difficult to doubt. Second, he is supposed to reply that " the 

 Germ-plasm of the first sire has in some way or another become 

 partly commingled with that of the immature ova " ; and Dr. 

 Romanes goes on to describe how there may be millions of 

 spermatozoa and " thousands of millions " of their contained 

 " ids " around the ovaries, to which these secondary effects are 



tions ** variations in Pscudotremia cavernamm and Tomocertis plumbeus, 

 found \\\'\n^ near the entrance to caves in partial daylight." The facts, as 

 accumulated by Mr. Packard, furnished a much more complete answer to 

 Pi-of. Lankester than is above given, as, for example, the "blindness of 

 Ncotoma, or the Wood-Rat of Mammoth Cave." It seems that there are also 

 " cave beetles, with or without rudimentary eyes," and " eyeless spiders " and 

 Mvriapods. And there are insects, as some "species of Anophthalmus and 

 Adelops, whose larvfe are lacking in all traces of eyes and optic nerves and 

 lobes." These instances cannot be explained as sequences of an inrush of 

 water carrying with it the remote ancestors,* some of which did not find their 

 way out ; nor can others of them be explained by supposing an inrush of air, 

 which did the like. 



* See "Social Organism" in Westminster Review for January, 1860; also 

 Principles of Sociology^ % 247. 



