OH, A TREATISE ON PILE. 43 



dark-brown, nearly black, then wax-yellow, and finally, black at the apex; the whole 

 ornamented with minute ochreons-colored dots and lines; the shade of darkness of tl.e 

 filament depending upon the number of these dots and lines. Transverse striae, minute 

 and irregular. Intermediate fibres, white and transparent, but marked with dots and 

 lines like the cortex. The centre, solid and white; no canal. A disk or tranverse section 

 shows an oval, dark-yellow figure, with a small, solid, white centre. Apex, abrupt, and 

 often furcated. 



The characteristics of this hair are : 1st, the variety of color upon the same filament; 

 2d, its peculiar formation, by the coloring matter being in the cortex and jibrom interme- 

 diate substance, and being disposed in dots and lines ; 3d, the absence of a central canal, 

 and central coloring matter. (See fig. 50 a and 50 b.) 



EXAMPLE OF THE COLORING MATTER OE THE PILE OF THE BAT. Examination and De- 

 scription of the Hair of the Bat: Vesper tilio Noveborensis ; order, Chiroptera; family, Vesper- 

 tilionidae; tribe, Bat. Specimen sent from Massachusetts, by Dr. H. Wheatland, of Salem. 

 Length, ^ to -^ of an inch; diameter, 1 of an inch; button, a slight swelling of the 

 lower extremity of the shaft only, with a pointed termination ; sheath, none discovered ; 

 follicle, none perceptible, after a rigid search. For the purpose of detecting it the dermis 

 was separated from the epidermis. The texture of the dermis is lined, that of the epider- 

 mis plain. Sheath, cortex, squamose ; scales, of that peculiar shape, that the shaft 

 appears like a succession or series of minute crucibles, nestled one in another ; coloring 

 matter, indistinct black ; bands at the superior surface of each crucible-shaped figure. 

 (See fig. 50 c.) Sometimes the coloring matter is interrupted, arid at others it is entirely 

 wanting. This last variety occurs near the superior termination of the stalk, which is the 

 cause that the fur there is, to the naked eye, of a lighter color than at the root of the 

 filament. Apex, generally very pointed, when in its natural state, but often appears to 

 have been broken. 



N. B. We have a specimen of hair from Paris, marked " Foil de Chauve-sourie," which 

 does not materially differ from the above described. 



There is a]so a specimen of a bat in the Academy of Natural Science, of Philadelphia, 

 called the African Bat, in which the scales of the cortex are shaped more like those of a 

 fish. The coloring matter is represented in figure 50 d. 



The characteristics of the hair of the Bat, (except the African,) so far as the above limit- 

 ed examinations and descriptions show, are, 1st, a variety of color in the same filament ; 

 2d, the peculiar arrangement of the coloring matter in the cortex and fibrous matter 

 being disposed of in borders to the crucible-shaped scales or rings; 3d, the absence of 

 a central canal and central coloring matter. 



The disposition of the coloring matter of some of the lower animals in dots, lines, rings, 

 &c., is often the cause of optical deception; the hair, to the natural eye, appears of one 

 uniform color, whereas, when placed under the microscope, it appears distinctly to be 

 two. For instance, the hair of a grey rabbit, when so examined, is found to be composed 

 of black rings with white interstices ; but they are of so small a diameter that they blend 

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