235 



Stress on upper comers of sternum. Upper C of 

 lung tips pivot for head socket movement. 



§ 182, No. 12. — Double action equalization, the pos- 

 terior lines leading. 



On the posterior lines (leading) ophidian spine. 

 Interchange between sides of lower C of central S 

 of inner bearings (reaction). This action, which, 

 in the preceding formation (§ 181), when superin- 

 duced on the outer bearing, completed the filling 

 of the lower lung lobes, by straightening the ribs 

 in "double twist;" now, on the contrary, having 

 only the efi'ect of pressing the ribs together, drives 

 the air fr*om these lobes. Interchange of inner 

 bearings between the sides of the upper C of the 

 central S (proper action). This action of the pos- 

 terior points of application draws the rib heads 

 down, and thus raising the outer part of their arcs 

 enlarges the upper lung lobes. This for the sec- 

 ondary section. For the primary section the pos- 

 terior cross-line ends separate between the lung 

 lobes, and, following this, the posterior points of 

 application, do the same, at the lowest dorsal ver- 

 tebrae.^ 



Composite Spine. — Again, the lower ribs are com- 



* What are "'points of application" for the "ophidian spine" come to 

 be cross-line ends for the " composite." 



