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are not already familar with the structure 

 of the part on which the saddle rests : — - 

 " Coming out at ahnost right angles to 

 the spine we have the ribs. Now as it is 

 indirectly on the ribs that we actually sit, 

 it is essential that we should have some 

 knowledge of the part. The ribs form a 

 case called the chest. This case is narrow 

 in front and wide behind. The ribs in 

 front, those situated under the fore leg, 

 are short, straight, wide, and fixed both 

 above and below ; as, however, w^e pass 

 backwards we find they become more 

 arched, narrow, and flexible. This arching 

 of the back ribs produces a very remarkable 

 change in size which can only be appreciated 

 by looking down on a horse as he is led 

 past you with nothing on his back. In no 

 position can it be better seen than from a 

 driver's seat of a London omnibus, as the 

 horses which work in these wear no other 

 harness than collar and traces, and the back 

 is exposed to full view. I can assure you 

 that a study from this position is of 

 inestimable benefit in learning how a 

 back works, but more particularly in obtain- 

 ing a correct appreciation of a point I have 

 to deal with presently, viz., the movements 

 performed by the shoulder blade. 



