ZOOLOGY. 359 



thenceforth loses all power of conception from intercourse with the 

 male of her own race. This was first pointedly stated by that very 

 intelligent traveller, the Count de Strezlecki, who has lived much among 

 different races of aborigines, the natives of Canada, of the United 

 States, of California, Mexico, the South American republics, the Mar- 

 quesas, Sandwich and Society Islands, New Zealand and Australia, 

 and who affirms that in hundreds of cases of this kind into which he 

 has inquired, and of which he preserves memoranda, there has not 

 been a single exception. As regards Australia and New Zealand, this 

 statement, strange as it seems at first sight, has been fully borne out 

 by independent evidence ; and it offers the most complete explanation 

 yet given of the very rapid decrease in the native population of the 

 various islands of Oceanica, in which European races have been long 

 established. Dr. Carpenter. 



THE FOUR DEGREES OF nYBRIDITY. 



THE following remarks are from a recent work of the late Samuel 

 George Morton, of Philadelphia : Hybridity, whether in plants or 

 animals, has been singularly neglected by naturalists. It has gener- 

 ally been regarded as an unit, whereas its facts are as susceptible of 

 classification as any other series of physiological phenomena. Hence, 

 I have proposed four degrees of hybridity. 



The first degree is that in which the hybrids never reproduce, in 

 other words, where the mixed progeny begins and ends with the first 

 cross. The second degree is that in which the hybrids are incapable 

 of reproducing, inter se, but multiply by union with the parent stock. 

 The third degree is that in which animals of unquestionably distinct 

 species produce a progeny which is prolific inter se. The fourth degree 

 is that which takes place between closely proximate species among 

 mankind, for example, and among those domestic animals most essen- 

 tial to their wants and happiness. 



OHIGIN OF THE DOMESTIC CAT. 



DR. RUPPELL decided that all our varieties of the domestic cat were 

 derived from one species, (Felis maniculata.) Fischer and Schink, who 

 are among the latest authors on synoptical mammalogy, refer the 

 above species, (which is yet wild in Nubia, and appears to have been 

 the parent of the common Egyptian house cat,) and the domestic cat 

 of Europe, to different species ; and Fischer further calls the F. mani- 

 culata " the parent of some varieties of the domestic cat." Temminck, 

 after admitting the Egyptian species as the common ancestor of our 

 house cats, adds, that " it is altogether probable that the crossing of 

 the Egyptian race with the wild one of our forests may have given 

 rise to an intermediate breed," but which, he adds, it would be im- 

 possible to prove by demonstrable evidence. Again, " It appears to 

 me probable that our house cats are derived from Egypt ; but that the 

 original race of Russia, known by the name of the Angora Cat, has 

 been produced from another wild type, yet unknown, and inhabiting 

 the northern regions of Asia. Milne Edwards and the learned editors 



