544 



PHYSIOLOGY OP 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 of 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 



