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given up the correlation-idea. I do not think it will have to be 

 the work of the experimental biologist to pass judgement upon 

 the merits of a given type, his work is the study of the genetic 

 factors, leaving the practical men to judge his combinations. 



The work of manipulating the genetic factors of the agri- 

 cnltural plants of all the different parts of one country can easily 

 be centralized, and done for a sum of money, insignificant in 

 comparison to the benefit the population in general would ultimately 

 derive from it, and undoubtedly most governments will realize 

 this importance and follow the example given by the government 

 of the United States. But for obvious reasons it is impossible to 

 do the necessary work with animals at one Station. The only way 

 to have this work done is to leave it to the practical breeder, 

 under supervision and advise of the experimental biologist. It is 

 not to be desired that the advise of this man will take the form 

 of showing the ideal towards which must be bred ; for, more often 

 than not, in the case of animals, the difficulty is not to produce 

 a not yet existing combination of genetic factors, but rather to 

 produce a homogeneous type ; a strain homozygous for all the 

 desired genetic factors. 



The practical men know very well what they want ; and it 

 remains for the experimental biologist to show them how they 

 can attain the goal they have set themselves. Often also, it will 

 be necessary for him, to devise experiments to find out, in how 

 far the desired effect depends upon a certain combination of 

 genetic factors, and in how far upon non-genetic factors, which 

 might be easy of control. Such experiments with animals can be 

 centralized in a certain way, by having the experiment-records 

 kept at the central experiment-station. In work with animals 

 everything has yet to be done from the bottom upwards. The 

 existing System of breeding animals, and above all of registering 

 them has resulted in a great many cases in a population in which 

 a minority have the desired genetic Constitution, the rest, though 

 nearly all bred from individuals, Coming up to this Standard, being 

 below it. In the first place it will in such cases have to be 

 ascertained in how far the desired result depends upon genetic 

 factors. It will be found that in most cases, such qualities as 

 appear difficult to fix are such which need for their formation the 

 Cooperation of a genetic factor, for which most of the individuals 

 are heterozygous. It will have to be taught the practical breeders 



