REPORT OF COMMISSIONERS OF INLAND FISHERIES. 239 



or heliotropic responses do not depend upon the specific characteris- 

 tics of the nervous system. Later day investigations have pointed 

 out that there may be wide differences between heHotropism in plants 

 and in animals, and that, although instinctive action in the daily 

 activities of the lower forms of life does, as Loeb argues, have its 

 basis in the same laws which determine the behavior of matter in 

 inanimate nature, still, in the light of these more recent investiga- 

 tions, it can not be denied that the behavior of these lower forms of 

 life is modified and even determined by the effect of stimuli, primarily 

 upon the nervous system. 



First we are to discuss the results of experiments which were car- 

 ried on under such conditions that there was no opportunity given 

 for the young lobsters to manifest any reaction whatever by their 

 efforts to swim in the direction of the incident light rays (phototaxis). 

 The results, then, must indicate a " choice " on the part of the lobsters, 

 of a specific degree of light intensity, light color (special rays), or 

 both. We shall, however, on a later page make reference to experi- 

 ments in which the phototactic responses (heliotropism in the sense 

 used by Loeb in the greater number of his papers) are discussed. 



The apparatus used for the experiments consisted of an oblong 

 wooden box, 4 x 6 x 18 inches on the inside. The box was blackened 

 and fitted with a light-tight cover, through one end of which pro- 

 truded, to a length of 6 inches, a cardboard tube 1| inches in diameter; 

 the function of this tube was to admit none but nearly parallel rays 

 of light into one end of the box, thus distinctly localizing the light 

 area (Plate XXXVIII) . In experiments wherein a white background 

 was required, the black interior of the box, as well as the under side 

 of the light-tight cover, was covered with a heavy grade of white 

 paper.* . 



The following description of the experiments, with some few 

 changes, is taken from the previous paper of the writer, already re- 

 ferred to. 



*The design of the box is based upon suggestions made by Keeble and Gamble, "The Col- 

 or Physiology of Higher Crustacea. Royal Society, London, 1904. 



