102 



GOOD FROM CROSSING. 



CiiAP. XVII. 



when no injury is perceptible from moderately close interbreeding, 

 y^et, to quote the words of Mr. Coate (who five times won the annual 

 gold medal of the Smithfield Club Show for the best pen of pigs), 

 " Crosses answer well for profit to the farmer, as you get more 

 " constitution and quicker growth ; but for me, who sell a great 

 " number of pigs for breeding purposes, I find it will not do, as 

 it requires many years to get anything like purity of blood 



" again." ^^ 



Almost all the animals as y^t mentioned are gregarious, 

 and the males must frequently pair with their own daughters, 

 for they expel the young males as well as all intruders, until 

 forced by old age and loss of strength to yield to some stronger 

 male. It is therefore not improbable that gregarious animals 

 may have been rendered less susceptible than non-social 

 species to the evil consequences of close interbreeding, so 

 that they may be enabled to live in herds without injury 

 to their offspring. Unfortunately we do not know whether 

 an animal like the cat, which is not gregarious, would suffer 

 from close interbreeding in a greater degree than our other 

 domesticated animals. But the jDig is not, as far as I can 

 discover, strictly gregarious, and we have seen that it appears 

 eminently liable to the evil effects of close interbreeding. 

 Mr. Huth, in the case of the pig, attributes (p. 285) these 

 effects to their having been " cultivated most for their fat," or* 

 to the selected individuals having had a weak constitution ; 

 but we must remember that it is great breeders who have 

 brought forward the above cases, and who are far more 

 familiar than ordinary men can be, with the causes which are 

 likely to interfere with the fertility of their animals. 



The effects of close interbreeding in the case of man is a 

 difficult subject, on which 1 will say but little. It has been 

 discussed by various authors under many points of view.^^ 



2^ Sidney (.n the Pig, p. 36. See 

 also note, p. 34. Also Richardson un 

 the Pig, 1847, p. 26. 



** Dr. Dally has published an excel- 

 lent article (translated in the ' Anthro- 

 polog. Review/ May, 1864, p. 65), 

 criticising all writers who b.ave main- 

 tained that evil follows from con- 

 sanguineous marriages. No doubt on 

 this side of the question many advo- 



cates have injured their cause by in- 

 accuracies : thus it has been stated 

 (Devay, ' Du Danger des Manages,* 

 &c., 1862, p. 141) that the marriages 

 ot" cousins have been prohibited by 

 the legishiture of Ohio ; but I have 

 been assured, in answer to inquiries 

 made in the L'nited States, that this 

 statement is a mere fable. 



