Galvanotropic Reactions of Polyorchis. 291 



cathode. The response depends In no way upon the connection 

 of these organs with the swimming bell, muscles or nerve-ring, 

 for it is obtained equally well with isolated tentacles and pieces 

 of tentacles. Isolated tentacles when placed transversely to the 

 current lines curve so as to assume a more or less complete U- 



FlG. 3. 



shape, with their concave side towards the cathode (Fig. 3). 

 When placed parallel to the current the tentacles do not curve 

 (Fig. 3» «)• 



If the tentacles are relaxed the making of the current causes 

 them to contract rapidly. Subsequently they turn their concave 

 side towards the cathode, and remain contracted for a consider- 

 able period. But if the current is continued long enough through 

 the isolated tentacles a partial relaxation comes on which is sud- 

 denly followed by another rapid contraction; so that we have, as 

 this process repeats itself, a slow and irregular rhythmic contrac- 

 tion caused as in the case of the quiescent frogs ventricle by the 

 constant flow of the galvanic current. If the current is continued 



Fig. 4. 



still longer in some cases a local anodal relaxation occurs and the 

 isolated tentacles then have the appearance of Fig. 4. As the 

 figure shows, this relaxation is at the bend of the U in the curved 

 tentacles and at the anodal end in those which were parallel to 

 the current lines and did not curve. 



