NEW VIEW OF THE MECHANISM OF RESPIRATION 289 



According to my researches both the opening and closing movements of the chest are vital acts. The function 

 of respiration is too important for any part of it to be left to irritabihty, extraneous stimulation, chance, or elasticity. 

 Besides we can, up to a point, breathe voluntarily and prolong the inspiratory and expiratory acts. This one fact, 

 while it effectually disposes of the mechanical theory of respiration, greatly strengthens the behef that the opening 

 and closmg of the chest are both vital movements. It, moreover, points significantly to the respiratory rhythmic 

 movements of the chest being fundamental endowments— that is, movements provided for before the animal is born, 



Fig. 55. 



Fig. 55. — Photograph giving a dorsal view of an athlete with the arms raised and the muscles of the arms and scapulae firmly 

 contracted and thrown into violent action. The muscles of the shoulder joints and the shoulder blades are particularly well seen. 

 They appear under the skin as great muscular rounded masses. This is especially tlie case with the deltoid and biceps muscles ; the 

 former on the left side assuming a horseshoe-shape on the top of the left shoulder ; the latter standing boldly out where the deltoid 

 tapers to a blunt point. The posterior edges of the scapulas are pressed firmly together, and the various muscles connected with these 

 bones are thrown out into strong relief. The muscles of the forearms are also well defined. Compare with Fig. 51, where the muscles 

 are carefully dissected and the reader can study them at leisure (the Author). 



and before either carbonic acid or oxygen are present in the lungs. As a matter of fact, the lungs of the foetus are 

 not distended, and it is only after birth and after the child has drawn its first breath that the mechanism of respiration 

 is brought into play. The first inhalation of air is a vital act, and so are all the opening and closing movements of 

 the chest which follow. That the gases in the lungs do not cause the respiratory rhythmic movements is abundantly 

 evident from the fact that the oxygen and carbonic acid are always present — in other words, are not present and 

 absent at stated intervals, which they would require to be if they produced the intermittent action of respiration. 

 There is no getting over this difficulty if the inherent power of the chest to open and close spontaneously be denied. 

 Moreover, it is the primary and only function of the chest to open and draw in air and to close and expel it. The 

 air can take no part either in its admission to the chest or its expulsion from it. The air holds exactly the same 

 VOL. I. 2 o 



