64 Adaptations of Fishes 
of the body. But when a current strong enough to be quite 
painful to the hands while handling the electrodes was used 
then stimulation of the fish called forth a brilliant glow of light 
apparently from every well-developed photophore. All the 
lines on the ventral and lateral surfaces of the body glowed 
with a beautiful light, and continued to do so while the stimu- 
lation lasted. The single well-developed organ just back of 
and below the eye was especially prominent. No luminosity 
was observed in the region of the dorsal organs previously de- 
scribed as rudimentary in structure. I was also able to produce 
Fie. 48.—Luminous organs and lateral line of Midshipman, Porichthys notatus 
Girard. Family Batrachoidide. Monterey, California. (After Greene.) 
the same effect by galvanic stimulation, rapidly making and 
breaking the current by hand. 
“The light produced in Porichthys was, as near as could be 
determined by direct observation, a white light. When pro- 
duced by electric stimulation it did not suddenly reach its 
maximal intensity, but came in quite gradually and disappeared 
in the same way when the stimulation ceased. The light was 
not a strong one, only strong enough to enable one to quite 
Say distinguish the apparatus used in the experiment. 
‘An important fact brought out by the above experiment is 
that an electrical stimulation strong enough to most violently 
stimulate the nervous system, as shown by the violent con- 
tractions of the muscular system, may still be too weak to 
produce phosphorescence. This fact gives a physiological con- 
