OF THE KINDS OF FEATHERS. 13 



(pennte, Kontur- or Lichtfedern) ; DOWN-FEATHERS (plumula, Dunen) ; SEMIPLUMES (pennoplumai, 

 Halbdunen) ; and FILOPLUMES, (filoplumee, Fadenfedern). To the latter I formerly gave the name 

 of arrested feathers (Kummerfedern). 



1. Contour-feathers may be the name given to the feathers furnished with a stiff and perfect 

 stem, which, being exposed to the action of light on the surface, form the external outlines of the 

 feathered body. The upper part, at least, of their vanes consists, to a greater or less extent, of 

 barbs, and usually also of barbules <& pennaceous structure, whilst the lower part, which is nearer 

 the tube, and concealed, has these parts usually downy, especially on the sides. The most perfect 

 contour-feathers, or those in which the pennaceous vane is largest and the downy part smallest, 

 are the remiges of the wings and the rectrices of the tail. In the other contour-feathers, which 

 are often provided with an aftershaft, the greater part usually belongs to the downy structure, and 

 it is precisely in these that we find exhibited the greatest variety in the different families, genera, 

 and species of birds, and also in birds of different ages, and even of different sexes. There are 

 also contour-feathers which are imperfect in various degrees. Thus, for example, some, which 

 have the upper part pennaceous, have no barbicels and booklets, such as those of the Ostrich 

 (Struthio) and Nandu (Rhed) ; others have no barbicels on the pennaceous barbs, as in the two 

 Cassowaries (Casuarius and Dromceus). Nay, there are some contour-feathers which are even 

 destitute of barbs, either on the parts most exposed to the light, as in the bristles of the angles 

 of the mouth and of the chin and the eyelashes (in which, however, a sort of vane occurs at the 

 lowest part), or throughout the whole shaft, as in the so-called wing spurs of the Indian Cassowary, 

 which I regard as feathers, although they possess no barbs, and depart from the regular form in 

 other respects. 1 



2. The down-feathers are recognised by the downy structure of all their parts ; they are 

 always found at a distance from the external outlines formed by the plumage, withdrawn from 

 the light and covered by contour-feathers, or by the folded wings. They frequently stand 

 between the contour-feathers, namely, one in the midst of the space enclosed by four of the latter, 

 so as to form, with them, a quincunx. This arrangement I have met with especially in Dysporus, 

 Podoa, and others. But we by no means always find a single down-feather between the four 

 contour-feathers, but frequently several of them ; as, for example, in the Unguirostres, in which 

 large and small ones occur together, and sometimes great numbers of them, as on the neck of 

 the Eagle. They are also found on spots which bear no contour-feathers ; or they occur on such 

 spots only, but are then more scattered. In this case they are certainly free from the usual covering 

 formed by the contour-feathers, and constitute the external outlines of the plumage, as, for 

 example, on the head and neck of certain Vultures ; but then the superior barbs possess compressed 



1 I cannot here suppress the observation, that to complete the character of the contour-feathers 

 we must notice their capability of being moved by peculiar muscles concealed beneath the skin. 

 These muscles start from the skin, and are inserted upon the portion of the tube which projects within 

 the skin, or more properly upon its sheath. It is true that these muscles, which are wanting to all 

 downy feathers, are sometimes so small, as not to be easily detected. But in some birds, especially in 

 members of the families Steganopodes and Unguirostres, I have distinguished them very readily on the 

 trunk, and indeed four, or more rarely five, of them to each feather, so that the total number of these 

 muscles must certainly amount to 12,000, as both in Anas marila and in Dysporus bassanus I have 

 counted about 3000 contour-feathers. 



