. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary. Birds; Ornithology; Oiseaux; Ornithologie. fM. 6 ClIANGKS OF (ii:. tant for purposos of classiticatioii. They liiivo l)peii specially studiptl, named and clussilicd \>y llic cclcljraUHl Nit/.scli, who has laid down tlic f'olIoAving as liic ircnoral ])lan ohfaininii' in liio vast majorily of hirds : — (/;.) 1. Tlic spinal or dorsal tract {j)feri/ht ftpiruiJt'x, pi. i, lig, 4, i), running a
. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary. Birds; Ornithology; Oiseaux; Ornithologie. fM. 6 ClIANGKS OF (ii:. tant for purposos of classiticatioii. They liiivo l)peii specially studiptl, named and clussilicd \>y llic cclcljraUHl Nit/.scli, who has laid down tlic f'olIoAving as liic ircnoral ])lan ohfaininii' in liio vast majorily of hirds : — (/;.) 1. Tlic spinal or dorsal tract {j)feri/ht ftpiruiJt'x, pi. i, lig, 4, i), running along tiu- middle of the bird above from nape of the neck to tho tail; sul)jcet to great variation in width, to dilation and contraction, to forlving, to sending ont branches, to interruption, etc. 2. Tiie Inuneral tracts {jit. /iKmcmlcs, pi. I, fig. I, j), always present, one on cadi wing; narrow bands running from the shoulder obliquely backward upon the upper arin- bone, parallel with the shoulder-l)ladc. .'?. The femoral tracts (pf. femo- vdJcx, \)\, I, lig. l,:i), a similar oblique band upon the outside of each thigh, but, unlike the last, subject to great variation. 4. The ventral tract {pi. ijdsfivrl, pi. I, lig. .'),s), which forms most of the i)lumagc on the under i)art of a bird; commencing at or near tho throat, and continued to the anus ; it is very variable like the dorsal tract, is usually bifurcate, or divided into right and left halves with a central apterium, is broad or nar- row, branched, etc. ; thus, Nitzsch enumerates nevenleen distinct modilica- tious! The foregoing arc mostly' isolated ti'acts, that is, bands nearly surrounded b}- apteria that are complementary to them; the following are contimiousl}', uniformly feathered, and therefore, in general, equivalent to the part of the body tlicy represent. Thus, 5, the head tract {pt. capil/'s, pi. T, figs, o, I; 4, i), clothes the head and generally runs into the beginning of both dorsal and ventral tracts. G
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbirds, bookyear1872
