4 INTRODUCTION. 



about the expansibility of the horse's nostril. The 

 thinness of the skin covering' the nostril is another 

 indispensable accompaniment of speed and wind. The 

 nostril of the cart-horse, with its thick skin, cannot 

 possibly expand to the extent which a blood horse 

 requires when at full speed. 



The False Nostril. — There is a curious formation 

 connected with the nostril of the equine race which 

 we do not observe in other animals. The whole of 

 the external opening does not conduct to the cavity 

 of the nose, but on the outer side there is a blind 

 pouch, called the false nostril, and formed by a doub- 

 ling of the skin. The use of these cavities is to 

 admit of that distention which the habits of the horse 

 necessitate. In the quiescent state, they permit of 

 the openings being diminished, without destroying 

 the symmetry of the face ; and, being muscular, they, 

 by their expansion, remove the atmospheric pressure 

 from the true nostril, when the passage of a greater 

 quantity of air is required. They permit the perfect 

 adaptation of the parts, without interfering with that 

 beauty of form which Nature, in all her works, studies 

 to preserve. In smell they are not concerned, but in 

 voice, neighing, &c, they are employed, giving cha- 

 racter and strength to the sounds emitted. 



The Cartilaginous Division of the Nostrils. — A piece 

 of cartilage runs up the centre of the nose, dividing it 

 into two cavities. There is, concerning this cartila- 

 ginous septum, or dividing wall, one circumstance 

 which deserves remark. From the more flexible 

 nature of the nostril, more of the membrane that 

 covers it is seen in the horse than in the ox ; and the 



