HYBRIDS IN A STATE OF NATUKB. 355 



quontly assume it as proved that cross-breeds may originate 

 from hybridisation which are both fertile and capable of trans- 

 mitting their characters to their descendants, but that certaialy 

 there is no m/ast in the case. 



An attempt may, however, be made to invalidate this posi- 

 tion by^ the assertion that, although the formation of such hybrid 

 races may be possible, it can only succeed with domestic animals, 

 and never in the freedom of nature and without the co-operation 

 of man, since in all the examples here adduced the cross-breed- 

 ing has been intentionally effected by man in animals kept in 

 captivity. I may at once admit that though I have so far men- 

 tioned none but such cases, it is not because cases of hybridisa- 

 tion in a state of nature have not been observed ; I have pur- 

 posely reserved the mention of them, and will now first briefly 

 allude to some rather doubtful examples. Felis torquata, 

 described and correctly drawn by Cuvier as a distinct species, 

 appears to be a hybrid, produced in a free state, between the 

 domestic cat and Felis benc/alensis ; Anas bimaculata is a freely 

 engendered hybrid between Anas hoschas and Anas crecca ; 

 Tetrao medius, in the same way, between T. urogaUus and T. 

 tetrix. Siebold's view is certainly well founded, that the vast 

 number of intermediate forms which constitute the crux of the 

 zoologist who endeavours to determine the species of the fresh- 

 water fishes of Grermany, must have originated from cross-breed- 

 ing in a state of nature ; this naturalist, in his well-known 

 work on the fresh-water fishes of Germany, enumerates no 

 less than eight hybrids, most of which have been described 

 by other zoologists, even as types of special genera. According 

 to Von Loewis, L^pus timidus and Lepus variabilis not un- 

 frequently produce hybrids. Dr. W. Wurm states that he 

 has often seen cross-bred partridges. J. von Kscher * asserts 

 that the polecat and ferret are two different species and 

 produce hybrids in a free state. The case noted by Mr. Buxton 

 is perfectly verified, of a male white cockatoo and a female rose- 

 coloured Leadbeater's cockatoo, which had never bred in con- 

 finement, and which when set at liberty in the woods near that 



* Director of the Zoological Gardens at Cologne. His sketclies of 

 animal life are well known in Germany 



