292 



STUDIES ON BIOLUMINESCENCE. XIV 



There is a second method of attacking the problem. Suppose we 

 prepare a solution which should contain medusa luciferin. On adding 

 this to a glowing extract of medusae, which must contain luciferin and 

 also luciferase to oxidize the luciferin, a brighter light should result 

 because within certain limits, with a given amount of luciferase, the 

 more luciferin is present, the brighter will be the light. Trials have 

 shown that no brighter light results from adding additional medusae 

 luciferin to a glowing medusa extract. Apparently, therefore, the me- 

 dusa luciferin solution contains no luciferin or the glowing extract of 

 medusae contains no luciferase; in other words, these substances do 



TABLE II. 



"Cross." 



Reaction. 



Aft/focowa luciferase + Mitrocoma luciferin. 



^quorea 

 it 



Cypridina 



Cavernularia 



» 



Cypridina 



Ptylosarcus 

 « 



Cypridina 



+ Cypridina 

 + Mquorea 

 + Cypridina 

 + Mitrocoma 

 + Mquorea 

 + Cavernularia 

 + Cypridina 

 + Cavernularia 

 + Ptylosarcus 

 + Cypridina 

 + Ptylosarcus 

 + Cypridina 



Negative. 



Brilliant light. 



not exist in the medusae. While my work thus far points to this con- 

 clusion, we should certainly expect so fundamental a reaction as that 

 of luciferin with luciferase to be universal. The statement that 

 luciferin and luciferase do not occur in medusae must therefore be 

 considered as tentative and dependent on the present state of our 

 knowledge. 



Specificity of Luciferin and Luciferase. 



The specificity of luciferin and luciferase is of considerable interest 

 apart from the question discussed above. Accordingly, I have made 

 a study of the luminescence resulting when Cypridina luciferin and 

 luciferase is mixed with these bodies prepared from other animals of 



