4C, OP PIGEONS AND FOWLS. 257 



does not also discern the relation, which is observable, 

 in every individual of eveiy species, between its sterility, 

 or the degree of its lessened fertility, and that amount 

 of the characters of its species, which it lacks. It is 

 equally strange, that such partial guess at the truth, 

 has not led him further, and revealed to him, that the 

 full and concurrent development of all the parts of a 

 species, is essential to physiological integrity, and to 

 full procreative power. It is, however, requiring too 

 much to expect a theorist to develop such a "lead," 

 when the absolute requirement of his hypothesis, is, 

 that many of the characters of each species should be 

 distributed, or apportioned, among several varieties. 



One type alone, of each species, is normal. Nature 

 errs not from her end, by the existence of a multiplicity 

 of types (i. e. varieties), in a species. For, for each and 

 every deviation from the one type, a penalty, com- 

 mensurate with such departure, is visited upon the in- 

 dividual. Nature, then, does not deviate from the type 

 prescribed; for every fact, in the whole of her realm, 

 attests most clearly, that physiological integrity can be 

 retained, only by strict conformity to the mould en- 

 joined. 



"Turning now to Birds," says Darwin (p. 154, Vol. 

 ii, Animals and Plants, &c), "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 became 



* * * small in the body, and bad breeders. He 

 produced the famous Sebright Bantams, by compli- 

 cated crosses, and by breeding in-and-in ; and since his 

 time, there has been much close-interbreeding with 



