430 LECTURE XV. 



number of deaths, must necessarily lead to final extinction. 

 The Mamelukes in Egypt could only maintain themselves by 

 the purchase and importation of slaves, as their own pro- 

 geny, notwithstanding all care, perished. Despite of all advan- 

 tages enjoyed by English married soldiers in India, they never 

 succeeded in rearing a sufiicient number for drummers and 

 fifers. The Dutch established in Java become sterile with 

 women of their own race, and, if they have any children, the 

 whole family regularly becomes almost extinct with the ap- 

 pearance of grandchildren. As generative capacity is the last 

 development of the organism, which is only unfolded when all 

 conditions of existence are present, so is it the first function 

 which fails, and soon ceases under hostile influences. As in 

 man, so is it in animals, many of which, though apparently in 

 excellent health, no longer propagate in captivity. Many 

 assertions of sterility of mongrels and hybrids, founded on 

 experiments in zoological gardens and menageries, rest merely 

 upon this diminution of generative power, observed also in 

 wild species, which are very prolific in a state of hberty. 



Let us now examine the changes which certain races are 

 said to have undergone, in which transplantation into other 

 countries has produced no diminution of generative power, 

 and where thus the conditions requisite for the formation of a 

 new race existed. First of all are mentioned the Negroes, 

 who, imported into Southern and Central America, are very 

 prohfic on that continent. The Northern slave-states, Virginia 

 and Kentucky, carry on the trade of slave-breeders, just as in 

 our own country there are cattle-breeders. Here we have 

 abundant materials for observation. Some authors assert, in 

 fact, that the Negroes imported into America, in successive 

 generations, gradually approach the white race. " The Negro 

 children of pure race," says Reiset, "born in the Antilles, 

 have all the characters of the Negro, but somewhat more 

 faintly developed. The colour and the hair remain the same, 

 but the muzzle diminishes, and in all other respects the 

 Creole-negro approaches the white." " The Negroes of the 

 IJnited States," says Reclus, "have by no means the same 

 type as the Negroes in Africa; their skin is rarely velvety, 

 though all their ancestors were imported from Guinea. They 



