OBSEllVATTONS ON SOUNDNESS. 
137 
lages belonging to the nose. The septum nasi is that which 
divides the two sides. Both sides are covered with mucous 
membrane. There are what have been termed true and false 
nostrils : the true are the larger, and which always are open; 
the false nostrils are small pouches, or cul-de-sacs, situated 
internally above the true nostrils. They are formed of integu¬ 
ment, which is exceedingly thin and soft. The Schneiderian 
membrane is, by some anatomists, called the pituitary mem¬ 
brane, from the nature of its secretion. It was formerly 
believed that this secretion proceeded from the brain, until 
Schneider^^ demonstrated and made known to the world 
that the secretion proceeded from the mucous membrane. 
It is closely attached to the periosteum, to the cartilages, 
and, in short, to all the passages and cavities of the nasal 
fossae; it is very thick, very vascular, and distinguished for 
its olfactory papillae ; it is strictly a mucous membrane, is 
pink in colour, but subject to change by cold, which is often 
produced by atmospheric influence. From the nasal fossae 
it may be traced through the nasal duct to the conjunctiva, 
along the Eustachian tubes to the pharynx and mouth, and 
from thence through the lungs and alimentary canal. It is 
very smooth on its external surface; the lateral nasal artery, 
the facial, and the palato-maxillary furnish abundance of 
blood for its secretion ; the first and fifth pair of nerves 
supply it with all it requires from this source. The olfactory 
nerves appear to be very sensitive; they ramify over every 
part of the mucous membrane, by which the horse is en¬ 
dowed, as it were, with the power of touch. Smelling, to 
the horse, is what touch is to man. 
When we contemplate the vastness of the mucous surfaces 
found in the equine race, more especially in the air-passages, 
we need wonder but little at finding a considerable quantity 
of fluid secreted in diseases of this membrane. It has been 
calculated that the number of air-cells in the human lungs 
amounts to six hundred millions. If this be an approximation 
to truth, and if the same might be compared with the in¬ 
creased volume of lungs in the horse, it goes far beyond my 
comprehension to imagine the extent of surface of the 
mucous membrane in our patients. 
I am free to admit most of us take but a hasty glance at 
this membrane when called to examine a horse as to sound¬ 
ness. If any quantity of discharge is found in either nostril, 
it is our duty to look closely at it; also to the submaxillary 
glands, and to the peculiarity of the cough, should one be 
present. I am anxious to impress this upon the minds of 
your readers, as 1 am convinced more animals are passed as 
