145 



§ 142. A a^ Formation of the secondary sec-^ 

 tion of tlie anterior winding-line in the ophidian 

 spine. The " point of apphcation " being on a 

 cross-plane section, somewhere at the root of the 

 neck, the ophidian left anterior Avinding-line de- 

 velops from it. This development causes the left 

 false and right true ribs to form on convexes of 

 the spine, which work against the sternum, and at 

 the same time expand the left posterior, and, al- 

 though less fully, the right anterior lung lobes, at 

 the expense of then- reciprocals, the collateral left 

 anterior and right posterior lobes."^ The con- 

 sequent changes in the centre of gravity bring the 

 left hind-foot and, in a less degree, the right fore- 

 foot on their outward bearings, giving them also a 

 greater share of the weight of the body, and by so 

 much, relieving the right hind and left fore-feet. 

 "With the movement of the false ribs the left side 

 of the diaphragm is stretched. 



The left fore-foot is turned in by the commence- 

 ment of an inward facing of its socket (§ 130), fol- 

 lowing through the upper part ^of the shoulder- 



* The anterior portion of the ej^e muscle rolls oatwarl with ih.Q fill- 

 ing of its diagonal posterior lobe, anfl inward with the exhausting of its 

 collateral posterior lobe. Hence, since it cannot roll two ways at once, 

 the two posterior lobes cannot hi reciprocals as to filling and exhaust- 

 ing. 



