213 



It will be also observed that the S S were carried 

 out by halves. 



§ 171. No. 4. — If for setting-up we begin with the 

 posterior lines of the bicomposite spine in the retro- 

 gressive pacing action, the successive motions would 

 be as follows : First. — For the bicomposite spine, 

 the hinder Umbs in reflected action, then the 

 shoulder-blades as the proper secondary section of 

 the posterior line ; the head-joint sockets equalize 

 at their anterior ends, next, for the composite 

 spine, the false ribs ; then the true ribs and filling 

 of the left upper lung lobe ; lastly, equalizing of 

 this secondary section in the ophidian S. Second. — 

 Head-joint sockets equalize on their outer edges, 

 the lower jaw articulations equalize on the inner 

 bearing, succeeded in the several spines by the equal- 

 izing of the posterior cross-line ends as the (right) 

 posterior point of apphcation draws. Third. — 

 The head condyle equalization at the rear ends, and 

 for the bicomposite spine, the lower jaw articula- 

 tions equalize on the outer bearing, then the hinder 

 limbs ; for the composite spine, the pelvis, false 

 ribs and filling of the (right) lower lung lobe, ac- 

 tion between upper and lower lung lobes. Fourth. — 

 Head condyles equalize on their cross joint move- 

 ment, equalization of shoulder-blades for bicom- 

 10 



