54 A HISTORY OF 



they ever appear disordered; those most remarkable for their courage, 

 then losr all their fierceness ; and such as are of a weakly constitu- 

 tion, often expire under this natural operation. No feeding can main- 

 tain their strength ; they all cease to breed at this season ; that nour- 

 ishment which goes to the production of the young, is wholly absorbed 

 by the demand required for supplying the nascent plumage. 



This moulting-time, however, may be artificially accelerated ; and 

 those who have the management of singing-birds, frequently put their 

 secret in practice They inclose the bird in a dark cage, where they 

 keep it excessively warm, and throw the poor little animal into an 

 artificial fever ; this produces the moult ; his old feathers fall before 

 their time, and a new set take place, more brilliant and beautiful than 

 the former. They add, that it mends the bird's singing, and increases 

 its vivacity ; but it must not be concealed, that scarce one bird in three 

 survives the operation. 



The manner in which nature performs this operation of moulting, 

 is thus : the quill, or feather, when first protruded from the skin, and 

 come to its full size, grows harder as it grows older, and receives a 

 kind of periosteum or skin round the shaft, by which it seems attached 

 to the animal. In proportion as the quill grows older, its sides, or the 

 bony pen-part, thicken ; but its whole diameter shrinks and decreases. 

 Thus, by the thickening of its sides, all nourishment from the body 

 becomes more sparing ; and, by the decrease of its diameter, it be- 

 comes more loosely fixed in its socket, till at length it falls out. In the 

 mean time, the rudiments of an incipient quill are beginning below. 

 The skin forms itself into a little bag, which is fed from the body by 

 a small vein and artery, and which every day increases in size, till it 

 is protruded. While the one end vegetates into the beard or vane 

 of the feather, that part attached to the skin is still soft, and receives 

 a constant supply of nourishment, which is diffused through the body 

 of the quill by that little light substance which we always find within 

 when we make a pen. This substance, which as yet has received no 

 name that I know of, serves the growing quill as the umbilical artery 

 does an infant in the womb, by supplying it with nourishment, and 

 diffusing that nourishment over the whole frame. When, however, 

 the quill is come to its full growth, and requires no farther nourish- 

 ment, the vein and artery become less and less, till at last the little 

 opening by which they communicated with the quill becomes wholly 

 obliterated ; and the quill, thus deprived, continues in its socket for 

 some months, till in the end it shrinks, and leaves room for a repeti 

 tion of the same process of nature as before. 



The moulting season commonly obtains from the end of summer to 

 the middle of autumn. The bird continues to struggle with this malady 

 during the winter ; and nature has kindly provided, that when there 

 are the fewest provisions, that then the animal's appetite shall be least 

 craving. At the beginning of spring, when food begins again to be 

 plentiful, the animal's strength and vigour return. It is then that the 

 abundance of provisions, aided by the mildness of the season, incite 

 it to love, and all nature seems teeming with life, and d sposed to 

 continue it. 



