53Q POPULAR SCIENCE MONTHLY. 



best pair of Andalusian fowls for any number of guineas. When he 

 breeds from them he finds, to his disgust, that only about half their 

 chickens, or slightly more, come blue at all, the rest being blacks or 

 splashed whites. Indignantly, perhaps, he will complain to the vendor 

 that he has been supplied with no selected breed, but worthless mon- 

 grels. In reply he may learn that beyond a doubt his birds come from 

 blues only in the direct line for an indefinite number of generations, 

 and that to throw blacks and splashed whites is the inalienable prop- 

 erty of blue Andalusians. But now let him breed from his ' wasters,' 

 and he will find that the extracted blacks are pure and give blacks only, 

 that the splashed whites similarly give only whites or splashed whites 

 — but if the two sorts of ' wasters ' are crossed together blues only will 

 result. Selection will never make the blues breed true; nor can this 

 ever come to pass unless a blue be found whose germ-cells are bearers 

 of the blue character — which may or may not be possible. If the se- 

 lectionist reflect on this experience he will be led straight to the center 

 of our problem. There will fall, as it were, scales from his eyes, and 

 in a flash he will see the true meaning of fixation of type, variability 

 and mutation, vaporous mysteries no more. 



Owing to the unhappy subdivisions of our studies, such phenomena 

 as these — constant companions of the breeder — come seldom within the 

 purview of modern science, which, forced for a moment to contemplate 

 them, expresses astonishment and relapses into indolent scepticism. 

 It is in the hope that a little may be done to draw research back into 

 these forgotten paths that I avail myself of this great opportunity of 

 speaking to my colleagues with somewhat wider range of topic than is 

 possible within the limits of a scientific paper. For I am convinced 

 that the investigation of heredity by experimental methods offers the 

 sole chance of progress with the fundamental problems of evolution. 



In saying this I mean no disrespect to that study of the physiology 

 of reproduction by histological means, which, largely through the stim- 

 ulus of Weismann's speculations, has of late made such extraordinary 

 advances. It needs no penetration to see that, by an exact knowledge 

 of the processes of maturation and fertilization, a vigorous stock is 

 being reared, upon which some day the experience of the breeder will 

 be firmly grafted, to our mutual profit. We, who are engaged in ex- 

 perimental breeding, are watching with keenest interest the researches 

 of Strasburger, Boveri, Wilson, Farmer and their many fellow-workers 

 and associates in this difficult field, sure that in the near future we 

 shall be operating in common. We know already that the experience 

 of the breeder is in no way opposed to the facts of the histologist; but 

 the point at which we shall unite will be found when it is possible to 

 trace in the maturing germ an indication of some character afterwards 

 recognizable in the resulting organism. Till then, in order to pursue 

 directly the course of heredity and variation, it is evident that we must 



