186 



are evidently developments on the alternate lines> 

 and we may therefore, instead of forcing the old 

 lines in order to form the equahzed alternates, 

 begin by forming the alternates and drawing from 

 the old lines. That is, instead of forcing A and B 

 in order to produce A and B, begin with forming 

 A and B and reducing A and B. 



In this case of beginning with the alternates,, 

 however, the direction of action will be, at every 

 point, reversed. For instance, in producing h'^ from 

 b'* the right true ribs are drawn around by the 

 right to the rear, being the movement in the sec- 

 ondary section of the right posterior lines ; but 

 beginning with h'^ these true ribs (the "right shoul- 

 der") are advanced, because the basis of action is 

 the left posterior line, which draws back the left 

 true ribs. 



Sixth, — The general course of the winding lines 

 of the hicomposite spine may be given as follows, 

 and since the object in Setting-up is to form these 

 lines by the fusing of those of the S S S, their 

 course should be thoroughly apprehended : 



The left anterior winding line in the hicomposite 

 spine passes from the left side of the head, through 

 the stemo-mastoid to the left upper comer of the 



