232 CROSSING AND CLOSE-INTERBREEDING. 



belief, is of some little value. Now, almost all men 

 who have bred many kinds of animals, and have 

 written on the subject, such as Sir J. Sebright, Andrew 

 Knight, &c, have expressed the strongest convic- 

 tion, on the impossibility of long-continued close-in- 

 terbreeding. Those who have compiled works on 

 agriculture, and have associated much with breeders, 

 such as the sagacious Youatt, Low, &c, have strongly 

 declared their opinion to the same effect. Prosper 

 Lucas, trusting largely to French authorities, has 

 come to a similar conclusion. The distinguished Ger- 

 man agriculturist, Hermann von Nathusius, who has 

 written the most able treatise, on this subject, which I 

 have met with, concurs." 



It is thus seen, that Darwin, while rightly conjec- 

 turing the cause of the evil effects upon the parts of 

 the organism, is puzzled, respecting the cause of the 

 effects wrought upon the aggregate — effects which are 

 evidenced in loss of fertility and of constitutional vigor. 



The experienced breeders and writers, of whom he 

 speaks, are unquestionably right, in their conclusion 

 that, as a fact, such effects do most frequently result. 

 But, they do not all refer them to "a great law of 

 nature," or to any other such " innate tendency," or 

 similar, metaphysical entity; and, then cpmplacently 

 imagine that they have explained (!) them. Fancy the 

 perfect howl of derision, which would be set up, by the 

 mutual admiration society of English philosophers, 

 were a person, suspected of being tinctured with or- 

 thodoxy, to attempt to shirk the solution of a body of 

 facts, by referring them to "a great law of nature!" 

 Breeders, whilst recognizing the truth of the facts, 

 advanced by Darwin, are not so obtuse, as to disre- 



