No..394.] THE UTILITY OF PHOSPHORESCENCE. 799 
are secured by what is known as “fire hunting.” In this same 
way the entomologist reaps a harvest by the aid of the electric 
light. The process would be analogous, perhaps, to what is 
known as “alluring coloration,” and its function in decoying 
prey. The phosphorescence would thus be of direct utility to 
the fixed ccelenterates in securing crustacean food. 
We may, I think, still further extend the application of this 
idea so as to include the attraction of Protozoa and even dia- 
toms. As already remarked, both of these groups of organisms 
contain many species that are strongly attracted by light, which 
appears to act as a direct stimulus to both unicellular animals 
and plants by virtue of its well-known effect on protoplasm 
itself. 
We thus see that all of the more important organisms upon 
which fixed ccelenterates feed are likely to be attracted by 
light, and it is reasonable to assume that phosphorescent light 
affects them in this manner. 
This, then, is the hypothetical explanation by which we may 
explain the possession of phosphorescent light by so many fixed 
Ccelenterata on the old Darwinian principle of direct benefit 
to its possessors, the benefit being the aid rendered in secur- 
ing food. 
