THE CIRCULATION. 



405 



fluences as will derange the circulatory system. The remarkable en- 

 ergy of the circulation through the blood-vessels is very finely illus- 

 trated by spreading and tying apart the toes of a frog's foot, and ex- 

 amining the web through a good microscope. The field of observa- 

 tion will appear like an immense plain cut 

 up with large rivers intersected by numer- 

 ous small streams, all running, with the 

 rapidity of a .torrent, the larger currents 

 running much the faster. The blood-cor- 

 puscles are also clearly distinguishable. 

 Something of an idea of this can be seen 

 by referring to Figs. 696 and 69t, which 



represent such a view of the circulation through the web. 



When the circulation is in its natural state, that is, distributed 

 properly to all parts of the body, it implies a state of perfect health, 

 but if, from any cause, it is withheld or forced from any part of the 



