186 
ANIMAL PATHOLOGY. 
the chisel of the sculptor, and the pen of the teacher, we shall un- 
derstand and admire the development of this portion of the nervous 
system in the most intellectual creatures, and the comparative 
want of it where the noblest of its purposes could not be accom- 
plished. 
The Construction of the Skin . — The skin or common integument 
of every animal is composed of three distinct layers or coats. The 
inner one, the corium, composed of dense filaments, crossing each 
other in every direction, presents beneath an irregular surface 
adapted to the adipose tissue on which it lies ; and, outwardly, 
a smoother face, but covered by innumerable little eminences or 
papillae. These are the projecting terminations of the nerves of 
sensation, and each seemingly covered by a delicate and vascular 
membrane, the prolongation or the termination of the proper 
neurilema or coat of the fibril. Upon these lies a viscid, semifluid 
substance, principally connected with the colour of the skin, and 
called the rete-mucosum : and, covering the whole, is the epi- 
dermis or cuticle, a pellicle of skin destined to protect the sub- 
jacent highly sensitive expansion, and perforated by innumerable 
pores through which a fluid exudes which gives a certain degree of 
flexibility to the whole. This applies to general sensation as 
well as to the sense of touch ; and sensibility, or common feeling 
chiefly, although not exclusively, resides in these terminations of 
the nerves in the true skin. 
The Sense of Touch continued.— There are some parts, 
however, of the frame where the surface of the corium is more 
thickly covered with these papillae than at others, or, in other 
words, where the terminations of the sentient nerves are mul- 
tiplied — where the epidermis is thin, and where the perspira- 
tion is abundant and continual. These are the parts possessed 
of the greatest sensibility. With them nature has usually con- 
nected great flexibility or freedom of motion, so that the ex- 
ternal object shall not only come in contact with them, but its 
form, its magnitude, its consistence, and many of its most im- 
portant qualities, shall be thoroughly examined and ascertained. 
Therefore, in the human being, the terminations of the nerves 
are multiplied, and the epidermis is thinnest, and the cutaneous 
perspiration is most constant, and the flexibility or freedom of 
motion is greatest, and consequently the sense of touch is 
also most perfect, and the knowledge of surrounding objects 
is thereby rendered most complete, and the mind is most en- 
larged. 
The Sense of Touch in inf erior Animals . Quadrumana. — Amidst 
considerable variety, dependent on the uses and destinies of 
different beings, there is much uniformity in all the works of 
nature. The hand — the fore extremity — is the organ of feeling to 
