SPIiCIES AND VARIETY. 229 



to the genera fringilla, anas, and phasianus, where such 

 unions are often fruitful, and produce prolific offspring. 

 The cock and hen canary-birds produce with tlie hen and 

 cock siskin and gold-finch * ; the hen canary produces 

 with the cock chaffinch, bull-finch, yellow-hammer, and 

 sparrow. The progeny in all these cases is prolific, and 

 breeds not only with both the species from which they 

 spring, but likewise with each other f. The common cock 

 and the hen partridge, as well as the cock and the guinea- 

 hen J, the pheasant and the hen §, can produce together. 



The anser cygnoides (Chinese goose,) copulates readily 

 in Russia with the common goose, and produces a hybrid 

 but perfectly prolific off'spring: the race soon returns to 

 the characters of the common goose, unless crossed again 

 with the Chinese species ||. 



It is true that these unnatural unions take place in ani- 

 mals under the power of man, are accomplished with the 

 assistance of contrivance and stratagem, and generally re- 

 quire an attention to several preliminary circumstances ; it 

 is also found, that, under artificial constraint and privation, 

 unions of distinct species may take place without fecunda- 

 tion, as of the hare and bitchy, the bull and mare** : they 

 prove, however, sufficiently that this affair of generation 

 will not afford the criterion we are in search of. 



It was soon found that this rule of reproduction could not 

 be applied to domesticated animals, on account of their un- 

 natural way of life; and hence Frisch, towards the begin- 

 ning of the last century, confined it entirely to the wild ones. 

 And here it is of little service : for how can we expect ever 

 to bring together those wild species to ascertain the point, 

 particularly when they inhabit different countries ; as, for 



* BuFFON, by Wood ; v. 14, p. 63. and followiiif^. 

 + Ibid. p. 70. iflbid. v. 12, 61. 



^ Pallas Spicil. Zool. f. xi. p. 36, note. 

 11 Ibid- Ant. Acad. Scient. Petrop. 1780; p. 83. note. P. 96. 

 S I'allas saw this in the instance of a tame hare kept with dogs. SpU 

 Zool. fase. xi. p. 36, note. 

 **BurFON, V. 4. p. 221. 



