202 CROSSING AND CLOSE-INTERBREEDING. 



most religiously by the most degenerate tribes of 

 Africa, show that it is a mere superstition, lingering 

 traces only of which prevail, and prevailed of old, 

 among the most cultured nations. Egypt, they say, 

 even in the zenith of her civilization, observed the pro- 

 hibition not at all ; and, they contend, that the preju- 

 dice has ever been least, in the regions around the Cau- 

 casus, where the proportionate development of Man 

 implies intellect above the average. The history of 

 the Ptolemies, whose frequent intermarriages between 

 brother and sister, during a period of 300 years, are 

 attested by history, affords, they contend, conclusive 

 proof that evil does not result. The history of Cleo- 

 patra, the last sovereign of that dynasty, though not 

 the last descendant, was certainly not, they urge, that 

 of a person, in whom any mental or physical degener- 

 acy was observable; although, they concede, with 

 delicate irony, that her moral comportment may have, 

 to some extent, betokened the evil. 



Nor is it to Man only, they say, that they must look 

 for evidence to sustain their position. Horses, sheep, 

 and cattle have been bred, inter se, in the closest rela- 

 tionship, for generation and generation following gen- 

 eration ; yet, no evil resulted ; but, on the contrary, 

 the animals displayed marked improvement. Many 

 special instances are given, where the horse has long 

 resisted breeding, in-and-in, between the nearest rela- 

 tions. The Leicester sheep have been bred in-and-in, 

 over sixty years, without the introduction of a single 

 new ram into the flock. With Cattle, the bull, " Comet," 

 is a well known instance of very close interbreeding. 



