﻿EXTERNAL ANATOMY. TARSUS. 



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thus become the most important parts of the leg, and we 

 shall now proceed to the details of each. 



(105.) The Tarsus, by which name we shall always 

 designate the shank, is either feathered, as in many of the 

 rapacious genera, or naked, as in the generality of birds. 

 The first of these different structures is most prevalent 

 in the owl family, where the whole of the legs, from the 

 thigh down to the claws, are generally covered with soft 

 feathers, those upon the tarsus and toes being short and 

 and compact. Several of the falcon family equally pos- 

 sess this structure ; but in these the toes are always 

 naked, as in the Buteo lagapus, or rough-legged buzzard 

 of Britain. The only instances of feathered tarsi which 

 occur out of the circle of the Raptor es, are found among the 

 Tetraonidcp, or grouse, where the feet and toes {fig. 59. a) 

 are generally as thickly clothed as any among the owls. 

 It has been thought that this additional clothing has 



ter, and we can have no doubt of the feet being 

 preserved much warmer by such a comfortable cover- 

 ing ; yet this reason totally fails in the case of the 

 owls, for these are spread over all latitudes, and many of 

 those from India have feathered tarsi, although the toes 

 are usually bare. The sand-grouse again, of the genus 

 Pterocles, which seem to delight in basking on the hot 

 sands of the African deserts, have their tarsi (ft) covered 

 with feathers, not so thick, indeed, as the ptarmigans, yet 

 still sufficient to serve as an additional covering. It is dif- 

 ficult, therefore, to arrive at any just conclusion regarding 

 the use of feathers upon the tarsi, because we cannot re- 

 duce the above facts to one common principle. 



(106). A naked tarsus is protected by scales. Next 



been given to 

 the grouse, the 

 greatest number 

 of which live in 

 the coldest re- 

 gions, as a pro- 

 tection to the 

 rigours of win- 



