34 mr. youatt’s veterinary lectures. 
them sufficiently. W here are the antagonists ? we find them 
only, and we find them of sufficient power, in the elasticity of the 
soft nostril generally, and more especially in that of the carti¬ 
lages. 
The difference of the Nostrils in different Breeds of Horses .— 
All these parts are more developed, the cartilages are larger, 
the integument is thinner, and more flexible, and the muscles 
are more powerful in proportion as the horse is formed for speed. 
There is not a more marked characteristic of the blood-horse than 
an expanded nostril. There is scarcely a more interesting object 
than his dilated nostril when he is sufficiently excited but not 
overblown ; on the contrary, there is nothing so painful to ob¬ 
serve as the spasmodic dilatation of the nostril, and the painful 
working of every muscle when the horse of no blood is pushed 
beyond his natural power. If you have ever contemplated the 
sudden lightening up of the countenance of the hunter, when his 
ears become erect, and his nostrils dilate as he first hears the cry 
of the hounds, and snorts and scents them afar off, you will be 
aware of the beauty and the use of an expanded nostril. Take 
the first opportunity of comparing together the confined nostril 
and thick skin, and quantity of cellular substance about the 
muzzle of the cart-horse with the far wider and more flexible one 
of the blood-horse. 
The inhabitants of some countries were accustomed to slit the 
nostrils of their horses, that they might be less distressed in the 
severe and continued exertion of their speed. The Icelanders do 
so at the present day: but there is no necessity for this, for na¬ 
ture has made ample provision for all the ordinary and even ex¬ 
traordinary exertion we can rationally require from the horse ac¬ 
cording to his breed and character. 
O # # 
The muzzle of the ox , not designed for speed, and incapable of 
the continued exertion of it, offers a singular contrast, especially 
connected with the different function of the upper lip in that 
animal, viz. firmly to hold the food until it is torn off, not per¬ 
fectly cut, by the pressure of the lower incisors against the pad 
which supplies the place of teeth in the upper jaw. In the sheep 
and swine no provision is made for speed ; but as I have already 
observed, it is secured in the dog, by the expanded and circular 
aperture of the nostril. 
The cavity of the nose is lined throughout by a soft thick 
membrane, extending from the common integument through its 
whole extent. 
Of Membrane generally. —As this is the first membrane 
which has presented itself to our consideration, I must say a few 
words of the nature and structure of membrane generally. It is 
