NERVES OF REPTILES. 



317 



fibres of the nerve, c, reflected upon the limb, F. In short, that 

 muscle will contract when the stimulating current has its origin 

 in a source external to that body. 



208 



Galvanoscopic leg, c, in connection with the rest of the frog, F, laid across a ' Galvanf s frog.' ccv. 



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

 the positive wire, 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 5 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 



