Lamenesses of Sheep and Lamhs. 
385 
are numerous small glands formed by involutions of the skin, and 
secreting an oily matter for its lubrication. These oil glands are 
particularly numerous about the fetlocks and pasterns. They 
especially abound between the digits and in an involuted pouch 
of skin called the biflcx canal situated in the upper part of the 
interdigital space. This canal is enveloped in cellular tissue, and 
measures about an inch in length. Its orifice readily admits the 
point of a large stocking wire ; it widens internally, curving 
backwards and upwards, and ends in a blind pouch. A number 
of hairs project from its orifice and an unctuous secretion oozes 
from it. The number of sebaceous oil glands which the cavity 
contains shows that its chief function is the elaboration of a lubri- 
cant oily fluid for obviating friction and keeping the skin soft, 
pliant, and protected from moisture. Investing the cofhn-bone, 
the deep layer of the skin becomes thickened, forming round its 
upper part a transverse vascular ring, from Avhich numerous 
sensitive leaves, or lamina?, pass downwards to the toe. On the 
lower or sole surface of the bone these laminae break up into 
numerous minute villous processes. Investing these vascular 
sensitive lamina*, and curiously dovetailed into them, lies the 
tough, insensible, horny hoof, corresponding exactly with the 
scaly insensible epidermis, of which it is but an expansion and 
modification. On the outer and anterior part of the hoof the 
horn is hard and brittle ; on the posterior and inner parts soft, 
thick, and elastic. The two horny projections behind tlie fetlock- 
joint closely resemble the hoofs in structure. Externally the 
horny matter is tough and firm and of a conical shape. Fitting 
into each cone is a mass of cellular tissue and fat, loosely con- 
nected with the tendons below, and joined to its fellow by a 
fibrous band. These two elastic pads act as buffers in obviating 
concussion, and by their horny coverings give an additional 
means of support and prehension. 
The limbs are abundantly supplied with blood. The large 
arteries from above after giving off many branches terminate in 
two principal trunks, one of which supplies each digit. These, 
after many subdivisions, terminate in minute tubes which consti- 
tute the great bulk of the sensitive laminae and supply them 
abundantly v/ith blood. The veins, returning the blood from 
these terminal ramifications, proceed up the limb in the same 
course as the descending arteries. To make up for the blood 
having to rise against the force of gravitation the veins are twice 
as numerous as the arteries. The nerves follow the same course 
as the vessels, and endow the vascular parts with acute sensi- 
bility. 
Sheep are not subject to such numerous or complicated lame- 
nesses as the horse. They are not subjected to violent or sudden 
