22 PTILOSIS OF THE HEAD. 



the occiput more than on the vertex or front, and this gives us the simplest 

 and commonest form. Such crests, when more particuhirly occipital, are usu- 

 ally connected with lengthening of nuchal feathers, and are likely to be of a 

 thin, pointed shape, as well shown in the kingfisher. Coronal or vertical 

 crests proper, are apt to be rather different in coloration than in specially 

 marked elongation of the feathers ; they are perfectly illustrated in the king- 

 bird, and other species of that genus. Frontal crests are the most elegant of 

 all ; they generally rise as a pyramid from the forehead, as excellently shown 

 in the blue jay, cardinal bird, tufted titmouse and others. All the foregoing 

 crests are generally single, but sometimes double ; as shown in the two lat- 

 eral occipital tufts of the "horned" lark, in all the tufted or "horned" 

 owls, and in a few cormorants. Lateral crests are, of course, always double, 

 one on each side of the head; they are of various shapes, but need not be 

 particularized here, especially since they mostly belong to the second class 

 of crests — those consisting of texturally modified feathers. It is a general 

 — though not exclusive — character of these last, that they are ieniporary ; 

 while the other kind is only changed with the general moult, these are as- 

 sumed for a short seasf)n only — the l)reeding season; and furthermore, they 

 are often distinctive of sex. Occurring on the top of the head they furnish 

 the most remarkable ornaments of birds. I need only instance the eleirant 

 helmet-like plumes of the partridges of the genus Lojjiioiii/x (186) ; the 

 graceful flowing train of tlie Oreorfi/x (gen. 18.5) ; the somewhat similar 

 plumes of the night and other herons. The majority of the cormorants, and 

 many of the auks, possess lateral plumes of similar description ; these, and 

 those of the herons are probably — inmost cases certainly — deciduous; while 

 those of the partridges above mentioned last as long as the general plumacre. 

 These lateral plumes, in many birds, especially among grebes, are associated 

 with, and, in fact, coalesce with, the ruff's, which are singular len<>-tbenino- 

 and modifying in different ways of feathers of auriculars, genre and gula ; and 

 are almost always temporar3\ Beards, or special lengthening of the mental 

 feathers alone, are comparatively rare ; we have no good example among 

 our birds, but a European vulture, GypaUos harbatus, is one. The feathers 

 sometimes become seedy (squamous) forming, for instance, the exquisite 

 gorglets or frontlets of humming-birds. They are often bris/li/ (setaceous), 

 as about the lores of nearly all hawks, the forehead of the dabchick, meadow- 

 lark, etc. While usually all the unlengthened head feathers point backward, 

 they are sometimes erect, forming a velvety pile, or they may radiate in a cir- 

 cle from a given point, as from the eye in most owls, where they form a disk. 

 In the foregoing, I only mention a few types, chiefly needed to be known 

 in the study of our birds ; but should add that there are many others, with 

 endless modifications, among exotic birds ; to these, however, I cannot even 

 allude by name. Peculiarities of nasal feathers, and others around the base 

 of the bill, are noticed below. Forms of crests are illustrated in fio-s. 21, 

 22, 23, 24, 32, 56, 95, 96, 107, 109, 114, 44-7, 125, 127, 135, 136, 152, 

 153, 154, m, 191, 202. /^^. ;yi_j^^ ^^^^^ ^_^^ 



