44 
ANATOMY OF THE HORSE 
by the canals pervading its interior for the transmission of blood¬ 
vessels and nerves. The very reverse of this is the case>ith the 
pastern and coronet bones: they (particularly the latter) are re 
markable for compactness and solidity of substance. 
THE NAVICULAR OR SHUTTLE BONE*, (os NAVICULARE.) 
Situation At the back of the coffin-joint, into whose compo 
sition it enters. r 
Form — Semi-lunar: its lunated border, however, will not make 
above one-third of a circle of such dimensions. 
Division— Into two surfaces; two borders; and two extremi¬ 
ties. 
Surfaces. The superior bears a corresponding aspect to the 
articulatory surface of the coffin bone, having two superficial la¬ 
teral depressions, with an eminence imperceptibly rising between 
them. Dividing the entire articular surface, formed by the two 
bones, for the reception of the coronet bone, into five parts, the 
navicular forms about two divisions.— The inferior surface is also 
articulatory; and also exhibits lateral depressions, but still more 
superficial than the superior, with an eminence across the middle, 
narrower and better marked than that above. Over this part 
plays the tendo perforans. 
Borders. — The lunated , broadest in the middle, narrowing 
towards the extremities, consists, superiorly, of a smooth narrow 
slip of surface along the middle, which is adapted to the bevelled 
portion of the articulatory surface of the coffin bone; and, below, 
of a fluted porous part, from which a broad ligament runs to the 
coffin.— The straight border is thin, compared to the opposite one; 
and is, superiorly, rough and porous, when the posterior ligament 
is attached; inferiorly, smooth and lipped, and continuous with 
the surface opposed to the tendon. 
The extremities , directed, one outward, the other inward, are 
obtusely pointed; and are fixed by lateral ligaments to the 
coffin bone. 
II.-THE HIND EXTREMITIES. 
Situation —Connected with the posterior parts of the trunk 
which they support. 
Division —Into haunch, thigh, hock, leg, pastern, coronet, and 
foot. 
* Sainbel calls it “ The Articular Bone.”—Girard considers it as a sesa¬ 
moid bone. —Our farriers, in their profound ignorance, have mistaken it for 
production of disease, and described it as “ the quit tor bone/’! 
