144 



STERILITY FROM 



Chap. XVIU. 



their own jjolleu, "but can easily "be fertilised \>y that of a 

 distinct species. Finally, we must conclude, limitt d as the 

 conclusion is, that changed conditions of life have an especial 

 power of acting injuriously on the reproductive system. The 

 whole case is quite peculiar, for these organs, though not 

 diseased, are thus rendered incapable of performing their 

 proper functions, or perform them imperfectly. 



Sterility of Doim'sficated Animals from chanrjed conditions. — "With 

 respect to domesticated animals, as their domestication mainly 

 depends on the accident of their breeding freely under captivity, 

 we ought not to expect that their reproductive system would be 

 affected by any moderate degree of change. Those orders of 

 quadrupeds and birds, of which the wild species breed most readily 

 in our menageries, have afforded us the greatest number of domes- 

 ticated productions. Savages in most parts of the world are fond 

 of taming animals ;^^ and if any of these regularly produced young, 

 and were at the same time useful, they would be at once domesti- 

 cated. If, when their masters migrated into other countries, they 

 were in addition found capable of withstanding various climates, 

 they would be still more valuable; and it appears that the animals 

 which breed readily in captivity can generally withstand different 

 climates. Some few domesticated animals, such as the reindeer and 

 camel, offer an exception to this rule. Many of our domesticated 

 animals can bear with imdiminished fertility the most unnatural 

 conditions; for instance, rabbits, guinea-pigs, and ferrets breed in 

 miserably confined hutches. Few European dogs of any kind 

 withstand the climate of India without degenerating, but as long 

 as they survive, they retain, as I hear from Dr. Falconer, their 

 fertility ; so it is, according to Dr. Daniell, with English dogs 

 taken to Sierra Leone, The fowl, a native of the hot jungles of 

 India, becomes more fertile than its parent-stock in every quarter 

 of the world, until we advance as far north as Greenland and 

 Northern Siberia, where this bird will not breed. Both fowls and 

 pigeons, which I received during the autumn direct from Sierra 

 Leone, were at once ready to couple.^ I have, also, seen pigeons 



*^ Numerous instances could be 

 given. Thus Livingstone ('Travels,' 

 p. 217) states that the King of the 

 Barotse, an inland tribe which never 

 had any communication with white 

 men, was extremely fond of taming 

 animals, and every young antelope was 

 brought to him. Mr. Galton informs 

 Qie that the Dnmaras are likewise 

 fond cf lieeping pets. The Indians of 

 South America follow the same habit. 

 Capt. Wilkes states that the Poly- 



nesians of the Samoan Islands tamed 

 pigeons; and the New Zealanders, as 

 Mr. ]\Iantell informs me, kept various 

 kinds of birds. 



°^ For analogous cases with the 

 fowl, see Reaumur, ' L'Art de faire 

 Eclore,' &c., 1749, p. 243 ; and Col. 

 Sykes, in * Proc. Zoolog. Soc.,' 1832, 

 &C. With respect to the fowl not 

 breeding in northern regions, see 

 Latham's ' Hist, of P>irds,' vol. viii., 

 1823, p. 169. 



