104 GOOD FROM CROSSING. Chap. XVII. 



instinctive feeling in man against incest any more than in 

 gregarious animals. We know also how readily any prejudice 

 or feeling may rise to abhorrence, as shown by Hindus in 

 regard to objects causing defilement. Although there seems 

 to be no strong inherited feeling in mankind against incest, 

 it seems possible that men during primeval times may nave 

 been more excited by strange females than by those with 

 whom they habitually lived ; in the same manner as accord- 

 ing to Mr. Cupples, 29 male deerhounds are inclined towards 

 strange females, while the females prefer dogs with whom 

 they have associated. If any such feeling formerly existed 

 in man, this would have led to a preference for marriages 

 beyond the nearest kin, and might have been strengthened 

 by the oil'spring of such marriages surviving in greater 

 numbers, as analogy would lead us to believe would have 

 occurred. 



Whether consanguineous marriages, such as are permitted 

 in civilised nations, and which would not be considered as 

 close interbreeding in the case of our domesticated animals, 

 cause any injury will never be known with certainty until a 

 census is taken with this object in view. My son, George 

 Darwin, has done what is possible at present by a statistical 

 investigation, 30 and he has come to the conclusion, from his 

 own researches and those of Dr. Mitchell, that the evidence as 

 to any evil thus caused is conflicting, but on the whole points 

 to the evil being very small. 



Birds. — In the case of the Fowl a whole array of authorities 

 could be given against too close interbreeding. Sir J. Sebright 

 positively asserts that he made many trials, and that his fowls, 

 when thus treated, became long in the legs, small in the body, and 

 bad breeders. 31 He produced the famous Sebright Bantams by 

 complicated crosses, and by breeding in-and-in ; and since his time 

 there has been much close interbreeding with these animals ; and 

 they are now notoriously bad breeders. I have seen Silver Bantams, 

 directly descended from his stock, which had become almost as 

 barren as hybrids; for not a single chicken had been that year 



29 ' Descfint of Man, 2nd. edit p. Review,' June, 1S75. 



524. 31 ' The Art of Improving the 



30 'Journal of Statistical Soc' June, Breid,' p. 13. 

 1875, p. 153 ; and ' Fortnightly 



