82 IXlKol'K T10N*. 



not always tten'e, even in :i state of nature. Still, it must be 

 observed that hybridity is much the most common among domesticated 

 annuals, and that the capacity for fertile hybridity is in proportion 

 to the aptitud ■ of animals for domestication. 



Dr. Bacbman (as has been seen before) rejects the authorities of 

 Dr. Morton, as unworthy of credit; among which authority 

 Buffbn, Temminck, Hamilton Smith, Cuvier, Chevreul, dvc In 

 snbsequenl articles* Dr. Morton gives additional reasons for li is 

 positions in regard ti> hybrids. Respecting hybrids of the sheep and 

 goat, the tarts of M. Chevreul wen- fully admitted by Bufibo and 

 Cuvier. The dogmatical assertion that tl are both of one 



species, and the quoted authority of Buffon in support of it. merit 

 no attention, sim-e Bufibn's opinion was founded solely on tin 

 that the camel and the dromedary produced a fertile «.ii- 

 sr. In Layard's plates of Nineveh are represented the camel and the 

 dromedary as distinct as they are now ; this dates as far bfl 

 2000 years before Christ. There can he no doubt that the wolf 

 and the dog copulate voluntarily, and that races have be d formed 

 in this manner. No one will probably pretend that all wolves 

 are of one Bpec though they maintain that the dogs 



are, and that the latter are the descendants of the former. Hy- 

 brids between the horse and ass are well known to be 

 prolific. As to hybrids in birds, we need only mention the hvhrid 

 grouse, (Tetrao medius,) which is very generally admitted to be the 

 mule-bird produced by the wood-grouse (T. orogallus) and the 

 black grouse (T. tetrix). This is now the opinion of Temminck, 

 who is " good authority" in ornithology; he confesses that he no 

 longer regards it as a true species, in a work published ten years 

 ago, though Dr. Bachman claims Temminck as showing the contrary. 

 at confusion has resulted from the habit of regarding hybrid- 

 ity as a unit, whereas its facts may be classified like other 

 series of physiological phenomena. Dr. Morton makes four /' 

 of hybridity. 1st. That in which the hybrids never reproduce, the 

 mixed offspring ending with the first cross ; this is the case with 

 almost all domesticated birds, however different their generic rela- 

 tions. 2nd. That in which the hybrids are incapable of reproduction, 

 inter se, but multiply by union with the parent stock ; this is the 

 case with the species of the genus Bos. 3d. That in which animals 

 of unquestionably distinct species produce a progeny prolific inter se ; 

 as the wolf and dog, and other species of the genus canis. 4th. That 



* Letter to Rev. John Bachman. and Additional Observations on 

 Hybridity in Animals. Charleston. 1850. 



