PRESIDENT S ADDRESS. 



827 



in its internal relations as process in the individual organism, or 

 in the external relations of organism to its outer environment. 

 And if we take refuge, as in the meantime we may still permissibly 

 follow Darwin in doing, in the idea of a "spontaneous 

 variability " of organism, this is of course to confess that we are 

 still unable to penetrate far enough into the ultimate mechanism, 

 if we conceive it as such, which underlies the admitted process of 

 organic modification. 



Professor Weismann, it is true, attempts wholly to eliminate 

 the action of environment in the production of variations, while 

 assigning to it the exclusive privilege of perpetuating the lucky 

 ones by its selective influence. But it will, I think, be found 

 difticult to do justice to the admitted influence of environment 

 upon the ordinary phenomena of the life of organisms and, as 

 even Weismann admits, upon their somatic structural constituents, 

 and yet jealously and rigidly to exclude these operations from 

 any modifying influence whatsoever upon the germinal consti- 

 tuents. And when even this is actually attempted the resulting 

 effort to account by germ structure for the spontaneous production 

 of the infinite variety necessary for a selection theory, introduces 

 yet another complication into the operations of that tremendous 

 mechanical apparatus of the germplasm, which has been conjured 

 up in explanation of the facts of hereditary transmission. Still 

 the mere fact that complication of this kind is the result consti- 

 tutes in itself no valid objection to the theory. But, in the last 

 resort, the expedient merely shifts the difficulty of a solution 

 from one sphere to another; and the dexterous compression of 

 the problem so as to enable it to be hidden out of sight in the 

 ultra-microscopical structure of the chromatin of the germ-cell, 

 even if legitimate, can hardly in the meantime be said to make 

 for simplification. 



Concerning the details of the argument between Weismann 

 and his critics I shall say nothing. The general verdict amongst 

 biologists in the meantime would appear to be that its results are 

 •so far inconclusive. But I may point out that Weismann's con- 

 tribution to the general theory of evolution may be regarded as 



