LUMINESCENCE OF MICROSCOLEX PHOSl'HOREUS DOUG. 2O3 



of Microscolex. The light of free living luminous bacteria, how- 

 ever, ceases quickly in this solution and the same was observed 

 by E. N. Harvey on the symbiontes multiplying in the luminous 

 organs of the two fishes, Photoblepharon and Anomalops, and by 

 me in Sepiola intermedia. 



The presence of oxygen is necessary for the luminescence of 

 Microscolex. It is obvious that the behavior of the earthworms 

 does not differ on this point from many luminous organisms such 

 as Cypridina, firefly, bacteria and others. In an atmosphere of 

 hydrogen the luminescence disappears quickly and does not 

 return on mechanical or electrical stimulation. After removing 

 the animals from hydrogen the luminescence appears again. 

 The luminous slime kept on a slide or the filter paper impregnated 

 with slime glows brightly upon moistening with water even after 

 an hour and a half. After this time no light can be observed. 

 Under the cover-glass however, if the edges be covered with 

 vaseline, the light appears after many days in the presence of 

 oxygen and water. This observation confirms fully the data 

 collected by Gilchrist in Chilota and shows that the disappearance 

 of luminescence points to the complete oxidation of the luminous 

 material. 



If the ground animals be mixed with water to which some 

 sodium hyposulphite has been added to remove the oxygen, and 

 a few drops of methylene blue which serves as an indicator for 

 the presence of oxygen, the light which appears on addition of 

 ether is visible after a longer time, and is brighter than in the 

 control tube without the sodium hyposulphite. The flash of 

 light is observed at the moment when on shaking, the oxygen 

 dissolves in sufficient quantity so as to change the colorless 

 methylene blue to the colored compound. This is apparently- 

 due to the nonoxidation of some of the granules, which were not 

 completely destroyed by the action of enzymes or perhaps to 

 the lessened activity of these enzymes due to the modified 

 composition of the solution. 



The different tissues of Microscolex contain a sufficient quantity 

 of oxygen to allow luminescence as proved by vital staining with 

 methylene blue. Nevertheless the light is not produced con- 

 tinuallv as in luminous bacteria, which fact must be taken as 



