196 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



Reactions to the Electric Current.'^ — The study of the reactions of the 

 lobster larvae to the electric current was a point of incidental interest 

 during the progress of the experiments on the reactions to light. 

 The current used was that from two to four dry cells, and the 

 exact strength, in the circuit, was never known. The long-applied 

 constant current was not employed, but a more or less interrupted 

 current, the flow of which w^as seldom permitted for more than four 

 to six seconds. The results are therefore qualitative rather than 

 quantitative. The larvae were imprisoned between two glass slides 

 placed vertically, parallel to each other, and about 2.5 centimeters 

 apart in a crystallization dish 10 centimeters in diameter. They were 

 thus confined in a rectangular area formed by the glass slides and the 

 sides of the dish, and between the two electrodes. These were made 

 of zinc strips wound with cotton and were hung over the rim of the 

 dish so that they dipped about 1.5 centimeters into the salt water. 

 The current was made, broken, or reversed by a rocking key. Usu- 

 ally the reactions of one larva were tested at a time. 



The results of the experiments may be briefly stated as follows: 

 (1) The larval lobsters of all ages reacted very definitely to the 

 electric current by gathering at the anCde. (2) Reaction to the 

 current took place only when the tail Avas directed to the anode, or 

 when the head was directed to the cathode and the back obliquely 

 to the anode. (3) The reaction took place as a result of rapid con- 

 traction and expansions of the abdomen. By this movement the 

 larvae were impelled backward to the anode. This method differed 

 from the mechanics of the reaction to light. (4) Although the 

 ascending electric current, as used, caused a progressive orientation 

 to the anode if the longitudinal axis of the larva came into proper 

 relation with the lines of the current, no current was apparently 

 ever itself instrumental in producing body orientation. (5) The 

 excitations arose and were strongest at the anode. Therefore, the 

 reaction of the lobster larvae to the galvanic current does not appear 



*The writer expects to publish soon the detailed results of his observations on the galvano- 

 tatic reactions of the larval lobsters. 



