14 REPORT — 1894. 



ture they want. But in natural selection who is to supply the breeder's 

 place 1 Unless the crossing is properly arranged, the new breed will never 

 come into being. What is to secure that the two individuals of opposite 

 sexes in the primeval forest, who have been both accidentally blessed with 

 the same advantageous variation, shall meet, and transmit by inheritance 

 that variation to their successors 1 Unless this step is made good, the 

 modification will never get a start ; and yet there is nothing to insure that 

 step, except pure chance. The law of chances takes the place of the cattle 

 breeder and the pigeon fancier. The biologists do well to ask for an im- 

 measurable expanse of time, if the occasional meetings of advantageously 

 varied couples from age to age are to provide the pedigree of modifications 

 which unite us to our ancestor the jelly-fish. Of course the struggle for 

 existence, and the survival of the fittest, would in the long run secure the 

 predominance of the stronger breed over the weaker. But it would be of 

 no use in setting the improved breed going. There would not be time. 

 No possible variation which is known to our experience, in tlie short time 

 that elapses in a single life between the moment of maturity and the age 

 of reproduction, could enable the varied individual to clear the field of all 

 competitors, either by slaughtering or starving them out. But unless the 

 struggle for existence took this summary and internecine character, there 

 would be nothing but mere chance to secure that the advantageously 

 varied bridegroom at one end of the wood should meet the bride, who by 

 a happy contingency had been advantageously varied in the same direction 

 at the same time at the other end of the wood. It would be a mere chance 

 if they ever knew of each other's existence — a still more unlikely chance 

 that they should resist on both sides all temptations to a less advantageous 

 alliance. But unless they did so, the new breed would never even begin, 

 let alone the question of its perpetuation after it had begun. I think 

 Professor Weismann is justified in saying that we cannot, either with 

 more or less ease, imagine the process of natural selection. 



It seems strange that a philosopher of Professor Weismann's penetra- 

 tion should accept as established a hypothetical process the truth of which 

 he admits that he cannot demonstrate in detail, and the operation of which 

 he cannot even imagine. The reason that he gives seems to me instructive 

 of the great danger scientific research is running at the present time — the 

 acceptance of mere conjecture in the name and place of knowledge, in pre- 

 ference to making frankly the admission that no certain knowledge can 

 be attained. ' We accept natural selection,' he says, 'because we must — - 

 because it is the only possible explanation that we can conceive.' As a 

 politician, I know that argument very well. In political controversy it is 

 sometimes said of a disputed proposal that it ' holds the field,' that it must 

 be accepted because no possible alternative has been suggested. In politics 

 there is occasionally a certain validity in the argument, for it sometimes 

 happens that some definite course must be taken, even though no course 

 is free from objection. But such a line of reasoning is utterly out of place 

 in science. We are under no obligation to find a theory, if the facts will 



