E. NEWTON HARVEY 213 



As I stated in my previous paper (Harvey, 1918-19, page 144), 

 "Acid thus favors reduction and hinders oxidation, while alkaH 

 favors oxidation and hinders reduction . . . . " so we may 

 now add, Hght favors reduction and darkness favors oxidation of the 

 luciferin ;z± oxyluciferin reaction. 



BIBLIOGRAPHY. 



Bach, A,, Biochem. Z., 1911, xxxi, 443; xxxiii, 282; 1912, xxxviii, 154; 1913, Hi, 



418. 

 Dubois, R., Compt. rend. Soc. hioL, 1918, kxxi, 317; 1919, Ixxxii, 840. 

 Harvey, E. N., /. Gen. Physiol, 1918-19, i, 133; 1919-20, ii, a, 133; h, 137. 



" Colucif erase + preluciferine = luciferine; 

 Luciferase + luciferine = oxyluciferine; 

 Oxyluciferine + oxygene = lumiere." 



Coluciferase forms luciferin from a precursor, preluciferine, and Byla's pep- 

 tone, lecithin, esculin, taurine, tyrosine, and asparagine will also form luciferin 

 if mixed with coluciferase. We may perhaps add that luciferin must have an 

 extraordinary chemical structure, if it can be formed from such diverse substances 

 as lecithin, esculin, and taurine. My own view of the processes involved in 

 luminescence is given in the text. 



In a later paper, appearing after my own (Harvey, 1918-19), Dubois (1919) 

 makes no mention of preluciferine and accepts in the case of Pholas my view that 

 luciferin can be again formed from a boiled extract of luminous animals by reduc- 

 tion. The enzyme of Pholas concerned in this reduction ("a hydrogenase") can 

 also liberate hydrogen from cane sugar. As this is Dubois's first mention of 

 luciferin formation by reduction, I fail to see how, as Dubois states, I "redis- 

 covered" this fact for Cypridina. 



