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GENERAL PHYSIOLOGY 



they collect in dense crowds. After the breaking of the current 

 they scatter again uniformly throughout the drop. Polytoma, 

 therefore, behaves toward the two electrodes exactly the 

 reverse of Paramcecmm ; in contrast to the latter it is anodically 

 galvanotactic. 



FIG. 232. Galvanotaxis of Amoeba proteus. At the left unstimulated and possessing numerous 

 pseudopodia. At the right, above, after making the current ; below, after reversal of the 

 current. The arrows indicate the direction in which the animal is creeping. 



A very fascinating spectacle results from exposing to the influence 

 of the current, at the same time, anodically galvanotactic Infusoria, 

 e.g., a flagellate form, such as Polytoma, and kathodically galvano- 

 tactic forms, e.g., a small ciliate genus, such as Halteria or 

 Pleuronema. The previously inextricable intermingling of the 



FIG. 233. Galvanotaxis of Amoeba ditfluens. A, Unstimulated, creeping; B, after making the 

 constant current. The arrow indicates the direction of the motion. 



two forms ceases at once after the making of the current. The 

 C'diata collect at the kathode, the Flayellata at the anode. After 

 a short time the liquid is entirely deserted in the middle, and the 

 two assemblages are sharply separated from one another. If now 



