488 
ROARING IN A HORSE. 
affected, any further increase of breathing would suffocate the 
animal, inasmuch as the cartilages would be held forcibly 
together by the rush of air, and the rima glottidis positively 
closed. 
The poor brute obtains no relief from its instinctive 
efforts to aid itself. The flanks work, the false nostrils 
dilate, a violent rush of air passes up them, which un- 
fortunately only adds to the evil, for the greater the atmos- 
pheric supply, the more powerfully are the cartilages driven 
together. 
And here, perhaps, a digression to the physiology of the 
“ false” nostrils would not be inappropriate. 
In man, and other animals of a similar organization, the 
air is inhaled both through the nose and mouth. Through 
the former under ordinary circumstances, but under conditions 
that call for increased respiration, the oral aperture is also 
unclosed. 
The nasal channels in man are not of sufficient calibre to 
transmit enough air upon the occasion of any extraordinary 
demand, the area of the glottal opening being greater than 
their united capacities. The additional supply is furnished 
through the mouth. 
In the horse, however. Nature has thought proper to 
depart from this arrangement; this animal breathes only 
through the nose, compensation being made in the peculiar 
formation of his nostrils. 
The nasal channels in the horse, unlike those in man, are 
highly capacious, and, although containing convolutions of 
the turbinated bones for the perfection of smell, possess a 
calibre sufficient for the transmission of as much air as, 
under any and every circumstance , can possibly pass through 
the glottal opening into the lungs. The only question being 
the means of collecting the extra quantity of air required, 
and regulating the supply to the exigences of the animal. 
The false nostrils afford this desideratum. The collapsed 
pouch which, when the horse is at rest, appears a mere cul- 
de-sac, expands in proportion to the demand for air, opening 
as his breathing proceeds, until, as seen under the excitement 
of the field or chase, it assumes that trumpet-like contour, so 
expressive of vigour, energy, and courage, that poetic hyper- 
bole has compared it to fire itself. In man, the nostrils 
alone are insufficient for the supply of air, whatever may be 
the size of their external opening. In the horse, the channels, 
being sufficiently large, he has only to dilate the false nostrils, 
and the demand is satisfied. Thus, for the purposes of 
respiration, the nostril of the horse combines the double advan- 
tages of nose and mouth in man. 
