OR, A TREATISE OX PILK. {) 



5th. In inclination, hair issuing out of the epidermis, at an acute angle thereto, while 

 tvool issues out of the epidermis at a right angle thereto. 



6th. In color, hair often assuming a variety of colors, while wool is generally white, 

 brown, or black. 



7th. In uniformity of color in a single filament; each separate filament of wool being 

 mono-chromatic; while that of the hair of some of the lower animals is often poly-chro- 

 matic. 



8th. In dimensions, hair being, generally, longer, and of a greater diameter than wool. 



9th. In exuberance, wool being produced, generally, in greater profusion, upon a 

 given area of skin, than hair. 



10th. In the apex, that of hair being less pointed, in proportion to the diameter. 



1 1th. In the disposition of the coloring matter of a perfect hair, being in a central canal, 

 which is not found in wool. (See fig. 2, a hair and b wool, contrasted.) 



OF FLEECE. The covering of sheep is called "fleece," from the Saxon "flys." It is 

 either hair, or wool, or a mixture of both.* 



PILE AND FEATHERS HAVE BEEN CONFOUNDED. Dr. Ure (in his Philos. of Manufac.) 

 says, "wool is a filamentous substance, which covers the skin of sheep and some other 

 animals, as the beaver, the ostrich, the lama, the goat of Thibet and Cashmere," &c., &c. 



Eble (in Die Lehre von der Haaren,) writes of the hair of birds. He says, "onlyym' 



Mrds possess stiff bristles and corneous hair, which we find more frequently with the 



mammalia; and it seems undetermined whether we are to count the fine down, which 



covers the body of a young bird before the formation of the real feathers, as hair or 



feathers." 



In Goodrich's Geography, p. 444, it is said that "the Rhea, or American Ostrich, has 

 black eye-lashes." 



And in Agasie's and Gould's Principles of Zoology, p. 151, it is asserted, that the 

 "chicken completely changes its covering from down to feathers " 



Eble also states, that "the male turkey has a tuft of stiff hair on his neck." 



To judge of the value of the above assertions, we must understand what is a feather. 



DESCRIPTION OF A FEATHER. (See fig. 3.) A feather consists of, 1st, a cylinder, at the 

 inferior extremity of which is a sheath, which connects it with the skin, but it has no 

 follicle. The cylinder is horny, is always of a circumference greater than that of its stalk ; 

 is transparent, or translucent, and terminates in a point more or less abrupt, which is 

 pierced at the posterior extremity. This orifice is called the "inferior navel," to dis- 

 tinguish it from another situated on the internal face, at the point where the cylinder 

 unites with the stalk, which latter is called the "superior navel." Inside of the cylinder 

 is a series of capsules, fitting one in another, and sometimes united by a central stalk, 

 forming a spire or chain. This series is called the "heart" of the feather. 



* There in no good reason for not extending it to that of the r/nat. 



