40 TRICILOLOGLA MAMMALIUM: 
lustre, considerable; direction, straight; undulated; button, spimdle-shaped, succeeded by 
a neck; shaft, cortex paved, divided into compressed pentagons, not well defined. 
Exception.—The cortex of the hair of the Sloth, does not appear to be either scaly or 
paved. 
Description or THE Hair or tne Turer-Toep Stiorn, (Bradypus tridactylis.)— 
Specimen in the Academy of Natural Sciences, of Philadelphia. Length, 2 inches and 
;{jths of an inch; color, dirty whitish-brown stone color, which, when viewed under the 
microscope, is found to be a mechanical mixture of irregular portions of the coriex, some 
of which are dirty white, and others brown color. Button, white, transparent, spindle- 
shaped; length, ;3, of an inch; diameter, ;1, of an inch; sheath, white, opaque, 
encompassing and adhering to the button; shaft, neck, cylindrical. naked, white, opaque 
and translucent; length, ;*,ths of an inch; diameter, 71, of an inch, gradually tapering 
from the centre both ways. Body, length, 1 inch ;%,ths; flat; greatest diameter, (which 1s 
10 
at the distance of 1 inch and ;*;ths from the neck,) jth of an inch, gradually tapering 
both ways toa diameter of ;4;th of an inch. The cortex, of the color above stated, of 
irregular, inelastic, brittle pieces, separated by dark lines, which sometimes open into 
cracks or fissures, extending to the central portion of the hair. When the cortex is 
removed, the cylindrical, elastic, central portion is seen of a diameter of 5+jths of an 
inch; sometimes a portion of the cortex may be removed, leaving the remainder adhering 
to the central portion, and presenting a rugged outline. At others, the central portion 
obtrudes from beneath the cortex, exhibiting their fibrous texture. The cortex will not 
divide into fibrils, but may be broken into irregular pieces of white and brown colors. 
The central part is divisible into fibrils. Apex, length, ,!th of an inch, naked, cylindrical, 
transparent and pointed. 
Ductihity, Elasticity and Tenactity.—One inch of the above hair, July 4th, 1849, Bar. 
30, Ther. 76, Dew-point, 66. 
With 170 grains it stretched 5, of an inch, elasticity entire. 
9 
“e 180 oc ce ae oe ce “ce 
“cc (73 ce 8 (73 73 7 Rt Ds 
190 oo minus 575 
ce ° (3 ‘ 10 ‘ ‘ “cc Bi 
200 5 90 : 90 
ce 9) 6“ be 12 6c oc 6c ye 
210 12 s 
a 220 * 6c 13 73 “cc ‘ 3 
ee oe 6c sé 15 be 6c oe ft 
230 15 a 
oe 9 ‘ ce 1: oe ce ce s_ 
240- ‘ Le sh 
SS 25 (Ve ac broke. 
While the hair was under the stretching operation, the sides of the cracks and fissures 
of the cortex separated; and they closed when the weight was removed, which shows that 
the central substance is ductile and elastic. 
The Wool of the same animal—The wool, when drawn out of the skin, is connected in 
tufts of 5, 7, or 9 filaments, held together by small portions of epidermis, below which 
a button is seen, and sometimes a button and sheath. Length, from 1 inch to 14; 
