47 



ary section brings around the upper end of its 

 cross-line, to the left and front, forming fully the 

 primary section of the left anterior winding line. 

 The head-ball passing further around comes to a 

 check, so as to press against a point toward the 

 front of the socket, and somewhat to the left of its 

 front centre. 



(b') (Which, in a part of its development pre- 

 cedes h, § 37). The now commencing active work- 

 ing of the right rear point of application does 

 not at first form the secondary section of its 

 winding line, which would form in the anterior 

 C of the S, that being prevented by the full 

 formation of the anteiior hne which has dis- 

 placed the upper end of the cross-hne, and thus 

 checks the movement of the lower end, so, 

 indeed, that this end cannot fully draw until 

 the discharge of the anterior line allows it to 

 come again into traction. The action, then first, 

 forms part of the primary section of the rear line, 

 and introduces the change of curve, from the cross- 

 line end, first IT? to the rear Cgivinj the counter-turn to 

 the ribs along its convex. Its effect in the head-joint 

 is to move the socket forward, but at the same time 

 with a turn to the right, which brings the left an- 



