NERVES OF REPTILES. 



317 



fibres of the nerve, C, reflected upon the limb, f. In short, that 

 muscle will contract Avhen the stimulating current has its origin 

 in a source external to that body. 



Galvanoscopic leg, 0, in connection with the rest of the frog, P, laid across a 'Galvani's frog.' CCV. 



Immerse each leg of a ' Galvani's frog ' in a cup of water, 

 the positive Avire, p, of a voltaic battery being placed in one 

 cup, the negative wire, n, in the other, as in fig. 209. In 



209 



Frog, as prepared by Galvani. p, positive wire : n, negative wire : of the battery ; o, connecting wire of 



the two vessels. 



the limb A the current runs in the reverse direction of that 

 of the volitional nervous force : in the limb b it runs in the 

 same direction. After the voltaic current has passed a short 

 time through the nerves, contractions occur in the limb b, not in 



