50 CONDITIONS OF THE HIND TOE. 



rare ; they are confined, among our birds, in any marked degree, to the two 

 genera of CaprimidgidcB (gen. 114, 115) and the turkey buzzard {Catliartes, 

 gen. 166) ; but among other Raptores besides Cathartes, such as certain 

 owls, and in some pigeons (knvest of Insessores , it will be remembered), 

 the toe is not quite down, or is even perceptibly uplifted. Technically, how- 

 ever, I take all these but the three first named, as having the toe down. It is 

 elevated in nil our Rasores or GaUince (gen. 177 to 188) ; elevated in all our 

 waders except the herons, ibises, and spoonbill; the elevation is least marked 

 in the rail family, but still plain enough there. It is elevated in all 

 swimming liirds, whether lolie-footed, or partly or wholly web-footed ; but 

 in the TodjKihnate order {ISteganojiodes, gen. 273 to 278) where it is lateral 

 and webbed with the inner toe, the elevation is slight. Now since, curiously 

 enough, the only three of our insessorial genera above mentioned (two of 

 Gaprimulgidcjn, and Guthartes) that have the hind toe well up, have also 

 little webs connecting the anterior toes ; and since some Rapiores are our 

 only other Insessores with any such true webs ; and since herons, ibises 

 and spoonbills are our only birds with such true webs, that have the hind 

 toe down, the following rule is infallible for all our birds: Consider the 

 hind toe up in every bird with any true webbing or lobing of the front toes, 

 except herons and their allies and some birds of prey. The converse, 

 also, holds nearly as well; for our only birds with fully-cleft anterior toes, 

 and hind toe up, are the rails and gallinules, the black-bellied plover 

 (our only 4-toed plover), the turnstone, the woodcock, Wilson's snipe, aud 

 most of the true sandpipers. Besides its versatility of position the hind 

 toe has 



§ 88. Other notable chaeactees. It is free and simp)le, in the vast 

 majority of birds ; in all Insessores, nearly all Oursores, and most JSTata- 

 tores. In length, it may equal or surpass (with its claw included) the 

 longest anterior toe, and generally surpasses at least one or two of them. 

 It is never so long as when down on a level with the rest ; here also, it 

 attains its greatest mobility, and among Passeres is virtually provided with a 

 special muscle for its apposition with the others in the act of grasping. In 

 general, it grows shorter as it gets higher up ; and probably in no bird 

 where it is truly elevated, is it so long as the shortest anterior toe. It is 

 short and barely touches the ground in most waders ; shorter still in some 

 swimmers, as the gulls, where probably it is functionless ; rudimentary in 

 one genus of gulls, Rissa (284), where it bears no perfect claw : represented 

 only by an immovaljle sessile claw, liable to be overlooked unless carefully 

 sought for, in the petrels; it disappears in the birds above named (§ 84), 

 and some others. It is never actually joined by direct soldering to cither of 

 the other toes, for any noticeable distance ; but is united to the base of the 

 inner toe by a web in the loons, and to the whole length of the inner toe in 

 all the Steganopodes (fig. 183). But it may be, as it were, independently 

 webbed; that is, have a lobe or flap of membrane hanging from it; this con- 

 dition is seen in all the sea-ducks {Fuliginoi, gen. 260 to 270), and in all 



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