E. NEWTON HARVEY 291 



mass relation between peroxidase and body oxidized, and it is not 

 impossible that some luciferases behave in this way. 



It should be pointed out in this connection that the light of these 

 jellyfish comes unquestionably from granules of relatively large size. 

 They can be seen at night under the microscope as dots of light with 

 definite boundaries, not merely points of light. These granules shine 

 brightly for some time, but if saponin or sodium glycocholate or 

 fresh water is added, the granules dissolve with a sudden flare of light 

 and then become dark. It is possible that the granule represents a 

 combination of luciferin and lucif erase in just the proper proportions 

 for utilization. In Cypridina no such luminous granules exist in the 

 extract (although granules occur in the luminous gland) or if they do 

 exist in the extract they are ultra-microscopic in size. 



It should also be borne in mind that Harden and Young^ found 

 an excess of zymase proper in some yeasts and an excess of co-zymase 

 in other kinds. There is a certain resemblance between the luciferin- 

 luciferase complex and the co-zymase-zymase complex and we may 

 have an excess of luciferin in some animals and an excess of luciferase 

 in others. Only if the latter condition existed could we demonstrate 

 the presence of these two bodies. 



I had hoped to solve this question by determining if the luciferin of 

 medusae will give light with the luciferase of some other form; i.e.^ 

 with a solution which we know to contain luciferase, as that of Cypri- 

 dina. Such a test has given absolutely negative results. The luci- 

 ferin of jEqiwrea, Mitrocoma, Cavernularia or Ptylosarcus, prepared in 

 various ways, will give no light with Cypridina luciferase. Neither 

 will the reverse "cross" {Medusa luciferase and Cypridina luciferin) 

 give luminescence. These results are given in Table II. 



This would seem to indicate that there was no Mitrocoma nor 

 jEquorea nor pennatuHd luciferin in the extract. There is a possibility, 

 however, that Cypridina luciferase is absolutely specific and will not 

 act with the luciferins of other forms. If that is the case, and my 

 work shows that luciferin and luciferase are specific, except for very 

 closely related forms, we cannot expect to throw light on the problem 

 by this method. 



' Harden, .\., and Young, W. J., Proc. Roy. Soc. Biol., 1906, l.K.xvii, 405; Ixxviii, 

 369 



