Phosphorescence in Ctenophores. 1 05 



In no case was any phosphorescence detected in the dead matter 

 originating from ctenophores. 



It was observed that after rough weather many ctenophores 

 were mutilated but nevertheless phosphorescent. Even separated 

 portions of the animal show this reaction both in the sea and in the 

 laboratory. Such pieces examined under the magnifier always 

 showed movements of the paddle plates and frequently muscular 

 contraction. In short, the pieces of the animal were found to be 

 alive. All the observations made gave the result that only the 

 living ctenophores or living parts of them phosphoresce. 



When either whole ctenophores of small size, or, much better, 

 excised parts from various regions of the animal were examined 

 under the magnifier in the dark, phosphorescence seems to be 

 present only along the rows of paddle plates. When the paddle 

 plates were numerous upon the excised piece, adjacent parts were 

 often so illuminated as to' make this determination uncertain. 

 But when portions of the jelly entirely free from paddle plates 

 were examined no phosphorescence was seen. Such jelly was 

 alive, for when the same preparation was examined in the daylight 

 muscular contraction could be seen in it. In the course of these 

 experiments no phosphorescence could be obtained from jelly 

 free from paddle plates. 



The smallest piece from which phosphorescence was obtained 

 consisted of four connected paddle plates with, of course, some 

 jelly adhering. Even single excised paddle plates were observed 

 to live for many hours or a day, as judged by their motion, and 

 yet all efix>rts to get phosphorescence from single excised paddle 

 plates were unsuccessful. 



The excised auricles showed, under the magnifier, cilia but no 

 paddle plates. No phosphorescence was obtained from them. 



The sense organ with adjacent parts was excised in a piece about 

 two centimeters long and one centimeter broad. Under the 

 magnifier no paddle plates were seen, but muscular contraction 

 was evident. No phosphorescence could be obtained from such 

 a piece. 



The previously described experiments with excised rows of 

 paddle plates, or parts of them, are sufficient to show that phos- 

 phorescence does not depend upon correlation of the part with the 

 sense organ. Whether cut in two transversely, or longitudinally 

 in such a manner as to leave the sense organ wholly in one part. 



