544 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



From these experiments it has been found that a heart will contract 

 rhythmically outside of the body, that this function is probably due to 



FIG. 226. SIMPLEST FORM OP MANOMETER FOR FROG'S HEART. (Sanderson.) 



(For description, see text.) 



the presence of motor ganglia, and that the heart may be slowed or 

 stopped either through inhibition from irritation of the inhibitory 



