98 



with all three S S S, finally depend directly upon 

 the head. 



Thus, although supported by the anterior ribs, 

 and adapting themselves to their motions, the 

 shoulder- blades (which carry the sockets of the fore- 

 limbs) have another connection, viz., that of the neck, 

 and move on a basis exterior to the trunk, during 

 the virtual crossing of the median line by those 

 ribs. During this time, the neck is the S of which- 

 ever fore-Umb is thus engaged. The quasi ball 

 and socket motion, at the base of the neck, is the 

 pivot on which either fore-hmb changes from the 

 trunk to the neck connection. 



The shoulder-blades are connected in rear with 

 the head by masses of muscle, and with the 

 whole back ridge of the spine, with the ribs and 

 with the pelvis, either directly or through the me- 

 dium of the upper part of the arm-bone, by sheets 

 of the same substance. To the neck part of the 

 spine they are not directly attached, but are joined 

 on either side by muscles to the whole length of 

 a cord or ligament, which, loosely attached to the 

 central rear line of the neck vertebrae, stretches 

 over them all, from the head to the projecting 

 bone of the lowest neck vertebra in man, and in 

 the horse to the top of the withers. 



