ANATOMICAL CONSIDERATIONS. 



25 



thick, fleshy screen, which hangs pendulous from the most backward 

 portion of the bony palate. 



In the previous diagram, figure 1 indicates the space allotted to the 

 nasal chamber, near the external opening to which will be observed the 

 numeral 8. The dotted lines surrounding the last figure represent the 

 dimensions of a blind pouch, or cul-de-sac, which separates the external 

 from the internal wall of the true nostril. The existence of such a pro- 

 vision has long been a puzzle to physiologists ; but, would these gentle- 

 men have given nature full credit for that care with which the Common 

 Parent studies to preserve the beauty of the higher order of His chil- 

 dren, and have considered that the horse's 

 necessity for different quantities of air varies 

 with different times and during different occu- 

 pations, they might have sooner comprehended 

 the utility of the development. 



Where the false nostril is placed is the only 

 poition of the nasal chamber which is not in- 

 closed by bone ; consequently it is situated at 

 the only place.-where the cavity admits of dis- 

 tenti»tn and or contraction. The animal, in a 

 passive state, breathes very leisurely ; at such 

 times the nostrils would sink inward, or be 

 deformed by the unavoidable collapse of the 

 wall, were not the false nostril present to per- 

 mit its diminution without materially affect- 

 ing the external form. But subsequent to 



severe exertion, everybody must have remarked the nostril spasmodically 

 strain, ass though each effort would crack the boundaries of the opening. 

 At such times the false nostril offers no stubborn opposition to the vio- 

 lence of respiration, while it serves to soften ^o^n the aspect, which, 

 if laid bare, might show too fearfully. 



A varied capacity for admitting air also presupposes a varied capacity 

 to alter the dimensions of the passages through which the atmosphere 

 travels to the lungs. If the reader will again refer to the facial diagram, 

 he will perceive a free space, in the center of which is placed the figure 

 6. These spaces (one on either side of the face) represent what are 

 termed the guttural pouches, they being merely bladders containing air, 

 and communicating separately with each nasal chamber. A bladder 

 with an external opening is of course most readily compressible. That 

 no doubt may be entertained of the use for which these vacant spaces 

 were established, they are placed immediately above the course of the 

 atmosphere to the lungs, and would contract or dilate according to its 

 volume. 



DIAGRAM OP THE FALSE NOSTRILS. 



1. The septum nasi. 2. The nasal 

 chambers. 3. The upper lip. 4. The 

 false nostrils. 



