412 Mr. N. A. Vicors on the Natural Affinities 
decisive of their affinity to them ; and it is by means of these 
characters that the passage from one order to the other is pre- 
served. If we now look among the Insessores for that tribe which 
approaches most closely to the Rasores, we may select the sin- 
gular African family consisting of the genera Musophaga Isert, 
and Corythaix Ill., which the accurate hand of M. Cuvier has 
already marked out as uniting the two orders. "The internal 
structure of these birds, at least of the latter genus, has been 
decided* by that discerning anatomist to be the same as that of 
the Perchers; and from their toes being arranged in pairs, al- 
though like those of many of the same tribe they are said to be 
retractile, they may be assigned a place among his Grimpereaur, 
or our tribe of Scansores. Their food and habits, and indeed their 
general appearance, on the other hand assimilate them to the 
Rasores. The well-known genus the Touraco of M. Le Vaillant 
approaches some species both of the Cracide and the Columbide 
by its bill; while the tail and wings of both Musophaga and 
Corythaix exhibit the exact form of the former family, or of the 
Linnean genus Crax, which meets the family of the Pigeons at 
the opposite extremity of the Gallinaceous order. It is conse- 
quently at this point of junction between the families of Colum- 
bide and Cracide, by means, as we shall see hereafter, of the 
genus Penelope of Merrem, that the second and third orders 
appear to be naturally connected. 
In pursuing the same line of inquiry, and exploring the pas- 
sage from the Gallinaceous to the Wading orders, we may remark 
a striking character in one of the groups of the former, which 
immediately suggests the union between them. The tribe of 
Cursores of Illiger have their affinity to the Wading Birds indi- 
cated by the length of their legs and their nakedness above the 
* « Leurs narines sont aussi simplement percées dans la corne du bec,—etle sternum 
(au moins celui du Touraco) n'a pas ces grandes échancrures ordinaires dans les galli- 
nacés."— Regne Anim. i. p. 435. 
knees : 
