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PTILOSIS OF THE HEAD. _ 



(e). No part of the body has so variable a ptilosis (§ 91^:*fie hea^^JPii 

 the vast majority of birds, it is ivliolly and densely ,;^]mered ;^^ii«nges 

 from this to wholly naked; but nakedness, it should De obsQtf^^MT means 

 only absence of perfect feathers, for most birds with dnfeatli^d heads have 

 a hair-like orowth on the skin. Our samples of nakedjit«iajfled birds, are the 

 turkey, the vultures, the cranes, and some few biii^'-of the heron tribe.'' 

 Associated with more or less complete "baldness," is frequently the presence * 

 of various fleshy outgrowths, as combs, waUles, caruncles (warty excres- 

 cences), lobes and flaj)S of all sorts, even to enumerate which Avould exceed 

 om- limits. The parts of the barn-yard cock exemplify the whole; among 

 North American birds they are very rare, being confined, in evident devel- 

 opment at any rate, to the wild turkey. Sometimes liorriy dilates take the 

 place of feathers on part of the head; as in the coots and gallinules. A 

 very common form of head nakedness marks one whole order of birds, the 

 Steganojyodes, which have mentum and more or less of gula naked, and 

 transformed into a sort of pouch, extremely developed in the pelicans, 

 and well seen in the cormorants. The next commonest is definite bareness 

 of the lores, as in all herons and grebes. A little orbital space is l)arc in 

 many birds, as the vulturine hawks, and some pigeons. Among water birds 

 particularly more or less of the interramal space is almost always nnfeath- 

 ered ; the nakedness always proceeds from before backwards. With the 

 rare exceptions of a narrow frontal line, and a little space about the angle of 

 the mouth, no other special parts of the head than those above given are 

 naked in any North American bird, unless associated with general baldness. 



(f). The opposite condition, that of redundant feathering, gives rise to all 

 the various crests (L., pi. crlstcB) that form such striking ornaments of many 

 birds. Crests proper belong to the top of the head, Init may be also held 

 to include those irrowths on its side ; these tojjether beimr called crests in 

 distinction to the ruffs, ruffles, beard, etc., of gula or mentum. Crests may 

 be divided into tAVO kinds : — 1, where the feathers are simply lengthened 

 or otherwise enlarged, and 2, where the texture, and sometimes even the 

 structure (§ 4) is altered. Nearly all birds possess the power of moving 

 and elevating the feathers on the head, simulating a slight crest in moments 

 of excitement. The general form of a crest is a full soft elongation of the 

 coronal feathers collective!}' ; when perfect such a crest is r/lobular, as in 

 the Pyrocej^halus (genus 111) ; generally, ho\v'sver, the feathers lengthen on 



white; or by unmarked change of a secondary color, as green into Ijlue or yellow. (2) Ijy obvious markings. 

 Markings are all reducible to two kinds, strealdnri and spotting. Streaking, as a generic tei-m, is sharply 

 divisible into lengthwiae and crosswise. LenQtluolse streaking comprehends all kinds of streaks, stripes, vitta?, 

 fascia3, with the distinctions above given in the text. Grossimse streaking is called barring, and always runs 

 transverse to the axis of a bird; if the lines are straight, it is handing; if undulating, it is leaving; if very 

 fine and irregular, it is verniiculation (L. vermiculus, a little worm). iSpotting is graded according to size 

 of the markings, from dotting or pointing, to blotching or splashing; and spots are also designated .accord- 

 ing to their shape, as round, square, U-shaped, V-shaped, hastate, sagittate, etc. Very fine spotting mixed 

 with streaking, is called niarhling; when indistinct, nebidation or clouding; intermediate special marks have 

 particular names, as crescents. Distinct round spots are oceMi ('^little eye.s "). Indistinct variegations of any 

 sort are called ohsolete. Washes of color over a definite color, are called tinges or tints. Color is glossy when 

 itshiues; 7?iezl(iZ/ic, when it glitters ; iridescent ^\\\Q.n \t changes with different lights. Colors are also bright 

 dull, dead (said of white), 02)aque, or velvety (said of deep colors, chiefly black), etc. 



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