102 GOOD FROM CROSSING. CnAP. XVII. 



when no injury is perceptible from moderately close interbreeding, 

 yet, 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." 24 



Almost all the animals as yet mentioned are gregarious, 

 and the males must frequently pair with their own daughters, 

 for they expe; 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 pig 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. 25 



24 Sidney on the Pig, p. 36. See cates have injured their cause by in- 

 also note, p. 34. Also Richardson on accuracies : thus it has been stated 

 the Pig, 1847, p. 26. (Devay, ' Du Danger des Manages,' 



25 Dr. Dally has published an excel- &c, 1862, p. 141) that the marriages 

 lent article (translated in the 'Anthro- of cousins have been prohibited by 

 polog. Review,' May, 1864, p. 65), the legislature of Ohio; but 1 have 

 criticising all writers who have main- been assured, in answer to inquiries 

 tained that evil follows from con- made in the United States, that this 

 sanguineous marriages. No doubt on statement is a mere fable. 



this side of the question many advo- 



