EFFECT OF ADRENIN UPON RATE OF LOCOMOTION. 159 



consisting of finely minced earthworms of raw meat, was supplied 

 two or three times a week, and at each feeding the water was 

 changed. The Parke, Davis, and Company preparation of 

 adrenalin chloride 1 was at first used; but it was found unsatis- 

 factory, as animals immersed in solutions varying from I : 1,000 

 to i : 20,000 soon became inactive, and died within less than an 

 hour. Solutions of the same strength, however, prepared from 

 adrenin in tablet or in crystal form did not produce the same 

 effect; and it seemed not improbable that it w T as the chloretone 

 in the first preparation which caused the rapid loss of activity. 

 To test this hypothesis, a solution of chloretone was prepared, 

 equal in strength to that contained in the adrenalin chloride 

 preparation, and a comparison was made of the effects upon 

 Planaria of similar dilutions of these two. In both cases com- 

 plete loss of locomotor power quickly resulted. The chloretone 

 alone (i : 2,000) was sufficient to cause within an hour, a notice- 

 able elongation and lack of response to mechanical stimuli, an 

 effect which is not surprising, since chloretone of i : 1 ,000 strength 

 is recommended as a ready anaesthetic for planarians (10). 



In the following experiments, therefore, adrenin in tablet and 

 in crystal form was used. In order to determine whether or not 

 this extract exercises any influence whatever upon Planaria, 

 active individuals were put into small bottles containing solutions 

 of adrenin of different strengths, and subjected to the influence 

 of the extract for varying periods of time. It was necessary to 

 keep the bottles corked to prevent the rapid oxidation of the 

 adrenin, but there was enough oxygen present to sustain the 

 worms; and the fact that planarians in corked bottles containing 

 water only were not affected seems proof that the results noted 

 cannot be attributed to lack of oxygen. In the preliminary 

 experiments it was found that animals in solutions of adrenin, 

 varying from i : 1,000 to i : 15,000 died in less than three days, 

 but in more dilute solutions they remained alive and active even 

 after a week. Most of the later experiments were, therefore, 

 made with a i : 15,000 solution, for one day, or with stronger 

 solutions for a shorter period. 



1 Each fluid ounce of this preparation contains f grain of adrenalin chloride 

 and 2\ grains of chloretone. 



