FEATHERS OF BIRDS. 395 



bllng in their arrangement the fibres of a camcl-liair pencil. 

 Each tuft contains about ten or twelve filaments, growing 

 from the upper ends of bulbous roots implanted in the skin, 

 and which are the rudiments of the organs that afterwards 

 form the feathers, of which this down, serving the purpose 

 of a first garment, hastily spread over the young bird, is but 

 the precursor; for the tufts generally soon fall off and disap- 

 pear, except in the rapacious tribes, as the eagle and the vul- 

 ture, where they remain attached to the feathers for a consi- 

 derable time. 



While this temporary protection is given to the integu- 

 ment, extensive preparations are making underneath for fur- 

 nishing a more effective raiment, adapted to the future wants 

 of the bird. The apparatus by which the feathers are to be 

 formed is gradually constructing; and its rudiments are re- 

 ceiving the necessary supply of nuti-icnt juices, and of ves- 

 sels for their circulation, together with their usual comple- 

 ment of nerves and absorbents. When first visible, this 

 organ has the form of a very minute cone, attached by a fila- 

 ment proceeding from its base to one of the papillae of the 

 skin, and establishing its connexion with the living system. 

 In the course of a few days, this cone has become elongated 

 into a cylinder, with a pointed extremity, while its base is 

 united to the skin by a more distinct bond of connexion 

 formed by the enlarged vessels, which are supplying it with 

 nourishment. It is in the interior of this cylinder that all 

 the parts of the feather are constructed; their earliest rudi- 

 ments being formed at the upper part, or apex of this organ; 

 and the materials of the several parts of the feather being 

 successively deposited and fashioned into their j)roper shapes 

 in different places: for while the first lamina? are construct- 

 ing in one portion of the cylinder, the next are only just be- 

 ^innins; to be formed in another; and while the outer covcr- 

 ing of the stem is growing from one membrane, the interior 

 spongy tissue is dejiosited in other places, in various stages 

 of softness or consolidation: so that the whole comj)oses a 

 system of operations, which may be said to resemble in its 



