1 82 



GENERAL ORNITHOLOGY 



carpus, or foot proper, metatarsus ; 7, digits with their phalanges, 

 of hand or foot, fingers or toes. Observe the improper popular 

 naming of these parts, in the case of the hind limb, whereby 1, 2, 3, 

 are not generally counted ; 4 is miscalled " thigh " ; 5 is miscalled 

 "knee"; 6 is miscalled "leg" or "shank"; 7 is miscalled "foot." 

 Observe also that in descriptive ornithology 6 is " ihe tarsus." 



The Plumage of the Leg and Foot varies Avithin wide limits. 

 In general, the leg is feathered to the heel, C, and the rest of the 

 limb is bare of feathers. The thigh is always feathered, as part of 

 the body plumage (pteryla femoralis). The crus or leg proper (thigh 

 of vulgar language, B to C) is feathered in nearly all the higher 

 birds, and in swimming birds without exception ; in the loons, the 

 feathering even extends on the heel-joint. It is among the walking 

 and especially the wading birds that the crus is most extensively 

 denuded ; it may be naked half-Avay up to the knee. A few waders 

 — among British birds, chiefly in the snij^e family — have the crus 



u^^^n 



Fig. 35. — FeathereJ tarsus of the prairie-hen, Cupidonia ciqndo. Nat. size ; from life by Coues. 



apparently clothed to the heel-joint ; but this is due, in most if not 

 all cases, to the length of the feathers, for probably in none of them 

 does the pteryla cruralis itself extend to the joint. Crural feathers 

 are nearly always short and inconspicuous ; but sometimes long 

 and flowing, as in the " flags " of most hawks, and in the American 

 tree-cuckoos (Coccyztis). The tarsus (I now and hereafter use the 

 term in its ordinary acceptation — C to D in Fig. 34 ; trs in Fig. 36) 

 in the vast majority of birds is entirely naked, being provided with 

 a horny or leathery sheath of integument like that covering the 

 bill. Such is its condition in the Fasseres and Ficarim (with few 

 exceptions, as among swifts and goatsuckers) ; in the waders with- 

 out exception, and in nearly all swimmers (the frigate-bird, Tachy- 

 petes, has a slight feathering). The Iiaj:)tores and Gallinoi furnish the 

 most feathei'ed tarsi. Thus, feathered tarsi is the rule among owls 

 (Sfrige^) ; frequent, either partial or complete, in hawks and eagles, 

 as in jiquila, ArchUmfeo, Faico, Buteo, etc. All British grouse, and 

 perhaps all true grouse, have the tarsus more or less feathered (Fig. 



