SITFAST. 
and the slightly hairy, S. hirtellwm, a frame plant, 
8 or 10 inches high, carrying white flowers in 
June and July, The name sisyrinchium signifies 
swine’s snout, and is supposed to have arisen 
from the fondness of hogs for the roots of the 
species to which the name was originally applied, 
—not a plant of this genus, however, but an iris. 
SITFAST, An indurated tumour on the back 
of a horse, occasioned by the pressure of the 
saddle. It generally requires to be dissected 
out, and should be done so gently and carefully ; 
and if the skin of the part be horny, it also must 
be removed. To detach the tumour slowly by 
rubbing with mercurial ointment or by blistering 
would involve more pain and trouble, and at the 
same time prove less efficient, than to dissect it 
out; and to tear it simply off with pincers would 
be brutal. The name sitfast is a barbarism, yet 
is not undescriptive. 
SITONA. See Weevit. 
SIUM. See Wartzr-Parsnip and Ponsa du 
SIZE. See Guur. 
SIZZING. Yeast or any similar ferment. 
SKEEL. A broad flat milk dish; also a large 
milking pail with two vertical handles, formed 
by two opposite projecting staves. 
SKEP. A bee-hive; also, a coarse, round, farm 
basket. 
SKID. A chain with which the wheel of a 
waggon is so fastened as to prevent it from re- 
volving on the descent of a declivity. See the 
article Drag. 
SKILLING. A bay ofa barn. 
SKIM. See Proven. 
SKIN. The natural covering of the body of 
animals. It defines the form of the body, pro- 
tects it from injury, modifies the action of the 
surrounding elements, indicates sensation from 
without to the interior parts, and comprises an 
inconceivably minute and complex texture of 
organisms for the offices of touch, of exudation, 
of absorption, and of many of the parts or con- 
comitants or dependencies of the highest func- 
tions of animal life. Volumes might be written 
to describe the wonders of the skin, and to 
explain how mightily and countlessly they dis- 
play the wisdom and beneficence of the Crea- 
tor. But we can afford, within our limited 
space, to do no more than give a general indica- 
tion of the skin’s structure,—and even this with 
reference only to the constitution and health of 
the domesticated animals. 
Three successive layers constitute the skin,— 
first, the cuticle, epidermis, insensible skin, or 
scarf skin,—second, the rete mucosum, or corpus 
mucosum,—and third, the cutis, corium, sensible 
skin or true skin; and two grand provisions exist 
everywhere in connexion with it as concomitant 
systems,—first, the hair, rising up from the cutis 
through the cuticle to a growth on the exterior, 
—and second, the panniculus carnosus, spreading 
beneath a great portion of the cutis of quadru- 
peds, and possessing more power and extent in 
SKIN. 227 
the thin-skinned and thin-haired than in the 
thick-skinned and thick-haired. 
The cuticle and the hair have already been 
sufficiently noticed in the articles Currcne and 
Harr. The rete mucosum is a thin, soft sub- 
stance, of mucous or mucilaginous consistence, 
extending between the cuticle and the cutis, and 
comprising the intricate ramification of minute 
nerves and blood-vessels which connects the in- 
fluences and agencies on the exterior of the body 
with the capacities and functions of the interior. 
Many of the vessels in its net-work are so minute 
that no magnifying power hitherto used can en- 
able the eye to trace them to their source; and 
part of them are said to contain a sluggish, stag- 
nant fluid, which constitutes the colouring matter 
of the disine while others bring up from within, 
and pour out through the cuticle, the fluid matter 
of either exhalation or exudation. See the article 
PrrspPrration. “ The minute vessels which sup- 
ply the exhalants cannot by any physical means 
be traced to their insertion into the blood-vessels ; 
and the physiology of this interesting portion of 
the animal economy is still in a very imperfect 
state ; nevertheless, that these ducts are con- 
nected with the blood-vessels is proved by their 
becoming filled with blood on friction of the 
skin, or by any bodily exertion which creates 
perspiration, or, in man, by certain actions of | 
the mind, such as modesty, shame, and anger.” 
The rete mucosum of a white man is white, of a 
mulatto tawny, and of a negro black; and that 
of a white-haired horse is white, of a brown-haired | 
one brown, and of a black-haired one black,— 
the rete mucosum of both man and beast being, 
in every instance, the seat of the colour or com- 
plexion of the body. 
The cutis or true skin is a strong, elastic, 
fibrous, exceedingly vascular, highly sensitive, 
intricately organized membrane. “It appears,” 
says Mr. Percivall, speaking of it particularly as 
it exists in the horse, “ to consist of a dense sub- 
stratum of cellular tissue, with which are inter- 
woven fibres of a ligamentous nature, in such a 
manner that innumerable areola, like the meshes 
of a net, are formed in it. These areole open, 
through correspondent pores in the cuticle, upon 
the external surface, and are for the purpose of 
transmitting thither blood-vessels and absorbents, 
giving passage to the hair, and lodging the vari- 
ous secretory organs of the skin.” It binds to- 
gether the different parts of the horse’s or ox’s 
or other animal’s frame; and is the substance 
which, when removed from the body and mani- 
pulated by the tanner and the currier, consti- 
tutes leather. See the articles Hipn and Leatumr. 
It is thickest in the most exposed parts of the 
body, and thinnest in the least exposed ; and it 
clings tightly to parts which have little or no 
local motion, and hangs loosely or even in folds 
on parts which have much local motion. “Its 
outer surface is garnished with numerous pa- 
pille, which are small eminences extremely sen- 
