470 JENNY— JOHN-CROW 



atlantic woods. The account of its habits by Alexander Wilson is 

 known to every student of ornithology, and Wilson's followers have 

 had little to do but supplement his history with unimportant details.^ 

 In this bird and its many allied forms, coloration, though almost 

 confined to various tints of blue, seems to reach its climax, but want 

 of space forbids more particular notice of them, or of the members 

 of the other genera Cyanocitta, Cyanocorax, Xanthura, Fsilorhinus, 

 and more, which inhabit various parts of the Western continent. It 

 remains, however, to mention the genus Cissa, including many beauti- j 



ful forms belonging to the Indian Region, and among them the ' 



C. speciosa and C. sinensis, so often represented in Oriental draw- 

 ings, though doubts may be expressed whether these birds are not 

 more nearly related to the Pies than to the Jays. 



JENNY, a child's nickname of the Wren., in the character of 

 Eobin Redbreast's wife. 



JERFALCOX, a vulgar corruption of Gerfalcon, that is Gyr- i 



FALCON. 



JOHN-CROW, the local name in Jamaica for what is elsewhere 

 in the New World called the Turkey-Buzzard, the VuUur aura of 

 LinniEUS, and Cathartcs or Catharista aura of most 

 writers ; to which, in 1874, Mr. Ridgway {N.-Am. 

 B. iii. p. 337) applied the generic term of Rhino- 

 gryphus, and Dr. Sharpe {Cat. B. Br. Mus. i. p. 25) 

 Cathartes aura. t]jat of (Emms. It is the most widely spread of 



(After Swainson.) . . -t7-,,^„^^^„^ • r j.i c< 



American Vultures, ranging from the Sas- 

 katchewan valley in Canada, under 55° of northern latitude, to 

 Tierra del Fuego, which is about as far south. This fact shews 

 its success in the struggle for existence ; but the zoologist should 

 not neglect the lesson taught by another fact. In Jamaica, 

 within a few years, the John-Crow, though there protected by 

 human law, has been nearly extirpated by the introduction of 

 the Mongoose (Extermination, p. 227, note 4), shewing how in- 

 adequately a successful animal can compete with conditions for 

 which it has not been prepared, and to which it is suddenly 

 exposed — the result of thus upsetting a natural law being fatal. 

 No notice of this bird, however brief, should omit allusion to the 

 controversy that once raged around it, in regard to the sup- 

 posed olfactory powers ascribed to it and other members of the 

 Sarcorhamphlda} as well as to those of the analogous Family Vulturidx. 

 Happily the whole mystery was dispelled by the simple "conjecture" 

 (as he modestly called it) of Canon Tristram {Ihis, 1859, p. 280), 



^ The "Blue Jaj' " of a recent American humourist wouhl, however, from the 

 locality assigned to his inimitable story, appear to be, not this species, but one 

 of its western kindred — American ornithologists must determine which. 



