OF CATTLE AND SIIKEP. 
267 
in the form of the internal or bony part of the horn. In the foetus 
of three months, there is no bony enlargement at the situation of 
the future horn ; but it soon afterwards begins to be visible, and 
at the seventh month there is a distinct tubercle, raising the skin. 
This continues to grow, forcing its way through the skin, and 
carrying with it the cuticle, which by degrees hardens over it. 
The horn, as it is commonly called, is composed of an elon¬ 
gation or process of the external plate of the frontal, covered 
by a cartilaginous investment or defence. This bony process, 
in its prolongation from the frontal, contains likewise a continu¬ 
ation of the cells, and it is vascular to a degree observed in no 
other bone. Its surface is furrowed and perforated by innu¬ 
merable vessels, which are designed not only for the nourishment 
of the bone itself, but of the horn by which it is covered. It is 
on account of this great vascularity of the bone, that, when the 
horn is broken, there is often so much hsemorrhage, and which 
the surgeon finds it very difficult to arrest. A veterinary friend 
who was compelled to amputate the horn of an ox, on account 
of an enormous bony excrescence that was forming on it, told me 
that the blood poured out in a stream as big as his finger, and 
which he could only stop by the long application of a large 
budding-iron. 
The continuation of the frontal sinuses through the horn will 
also enable us to account for the violent inflammation w T hich often 
follows a fractured horn. The injury of the membrane would be 
a sufficient cause of inflammation; but air is admitted, not in¬ 
deed into a cavity from which it had before been altogether ex¬ 
cluded—it is not a serous membrane,—but where it had not free 
access, and the unaccustomed stimulus produces great irritation. 
Farriers and cowleeches are properly anxious to close the open¬ 
ing. They place over it plaister upon plaister of tar or pitch, not 
merely to restrain the haemorrhage, but to exclude the air. 
The bone of the horn once broken off is never reproduced—at 
least not perfectly so. Nature often attempts to restore a lost 
portion of the frame, but the process is irregular, and the pro¬ 
duct misshaped—an irregular mass of bone is occasionally form¬ 
ed on the fractured part of the horn. I have one that weighed, 
when first separated, no less than thirty-seven pounds. The horn, 
however, of its natural form, and with its natural investment, is 
rarely or never produced. 
The covering of the bone differs little in construction from the 
horn of the foot of the horse. It is composed principally of 
coagulated albumen with a small portion of gelatine, and about 
a half per cent of phosphate of lime. The albumen is somewhat 
greater in quantity in the horn of the ox, and hence its supe¬ 
rior hardness. . It is divided by maceration, and even mechani- 
