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 



Calvauoscopic leg, G, iu cniiiicction wiUi Ihc rest of the frog, f, laid across a 'Clalvani's frog.' ccv. 



Immerse each leg of a ' Galvanl'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 propaitd t-i t-. ilvani. p, positive wire : N, negative wire : of tire liattery ; 0, 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 



