158 



AYES. 



the accessory plame is large, but of soft and downy texture : others have it reduced to 

 a small tuft of down ; while in many it is absent altogether. In some Birds, the 

 vanes of the feathers are to a variable extent united, or soldered into an uniform mass , 

 and there are various additional modifications, too numerous to admit of detail]. The 

 touch must be feeble in all parts that are covered viith them ; and, as the beak is 

 almost always corneous and but little sensitive, and the toes are invested with scales 

 above and a callous skin underneath, this sense can be of little efficacy in the class of 

 Birds. [In the Snipes and Lamellirostres, however, the sense of touch in the bill must 

 be delicate, as testified by their manner of feeding, as \vell as by the many nervous 

 papilla: distributed over its surface. The enormous bill of the Toucans, also, is 

 very sensitive ; and even the hardest bills are traversed by ramifications of the fifth 

 pair of nerves, which terminate in scattered papilla'.] 



The feathers are cast t\\'iee in the year [in some instances, but by far the greater 

 number of Birds renew their plumage in autumn only ; and in no instance are the 

 v.ing-priniaries shed excepting in autumn, or at that moult which corresponds to the 

 autvunnal moult. Many, as the Hawks, larger Gulls, Skc, retain their entire nestling 

 garb till the second autumn; while others, as the Crows, Starlings, &c., renew every 

 feather previous to the first winter ; and there are some groups, as that of the 

 Thrushes, together with various ctouble-movltbig Birds, as the Pipits and Wagtails, 

 which change their first clothing plumage soon after cjuitting the nest, but retain their 

 nestling primaries until the second autumn — (that is, until the third renovation of the 

 body feathers). In the Cormorants, Grebes, &c., some additional ornamental plumes are 

 developed towards the commencement of the breeding season ; at wdiich time various 

 other Birds undergo a change of colour, unaccompanied Ijy any moult * ; while others, 

 again, cast the terminal portion (commonly of a dingy hue) of the greater number of 

 their feathers, whicli during winter had concealed the brighter tints of summer ; two 

 or more of these various modes, by which a seasonal alteration of appearance is eftected, 

 being frcrjuently simultaneously obsen-able in the same individual.] In certain species, 

 the winter plumage differs in its colours from that of summer; and in the greater 

 number, the female differs from the male by colours less vivid, and the 3-oung of both 

 sexes then resemble the female. When the adult male and female are of the same 

 colour, the young have a peculiar livery. [As thus expressed, however, these rules 

 require to be qualified by numerous exeejitions : the true enunciation of them being, 

 that, when the plumage of the young differs from that of the adult male, or of the 

 female in those few cases where (as in the common GaUinule) this sex is the brighter, 

 that of the other sex may be simUar to either of those extremes, or is in various 

 degrees intermediate : the male and female of the common British Redstart, for 

 instance, are dissimilar, and the young do not resemble the adult female ; but the 

 garb of the latter is intermediate to those of the adult male and j^oung.f ] 



» When tills fnkcs plftce, as in certain Cambets [ToliKiii!^, the 

 colouring mutter ia often etjtirely absorbeil previously lo tlie autumnal 

 elianffc of featlier ; and hi some double-iLiouItinii species, as theGolrlen 

 Plover, it connnotily happens in sprinff that the colourinij secretion 

 fingcs the ohl feathers that are loose, niid ready lo drop off ,— thus 

 ]jrovin£( that a circulation obtains in the pores of feathers, even up to 

 the period of tlieir being naturally east, — Ro. 



t There is a typivui state of plumage in most groups of Birds, which, 

 in ( criaiii species, as the Tree Sparrow, is common to ohl aiLd young 

 of lioth sexes ; hat which is very usually obtained only by the adult 

 iLirile, as is observable in the eouooon Hou-e Sparrow ; in ti,e nobiii, 

 Goldfinch, &e.. to select other familiar CKaiuples, it is acquired by the 



aduits of both se\es ; and. in the Common Galiinnlc, only by the 

 mature female. There are also many Birds in whicli neither sex 

 assumes this comparatively advanced livery i the larger Bitterns, for 

 example, both sexes of which permanently retain the markings and 

 style of colouring characteristic of only the first or immature dress of 

 the Uwarf-bitterns (subgenus Ardfotu); the adult male common 

 Bunting [Etiib'Tiza viili/iria), also, thus exhibits correspond- 

 iiig livery to that jiroper to the females and young of ihe rest of its 

 group, never advancing, like the m ales of the otlier species of Bun ting, 

 beyond its priinitlve nestling colours and markings. We are led to 

 recignijc, therefore, two extreme conditions of plumage as regard, 

 the colouring,— one generally, but not always, cliaraetcristic of mata 



