354 THE BEAUTIES OF NATURE CHAP, 
organs flash out must present a very remark- 
able appearance. 
We have still much tog learn as to the 
structure and functions of these organs, but 
there are cases in which their use can be 
surmised with some probability. The light 
is evidently under the will of the fish.’ It is 
easy to imagine a Photichthys (Light Fish) 
swimming in the black depths of the Ocean, 
suddenly flashing out light from its luminous 
organs, and thus bringing into view any prey 
which may be near; while, if danger is dis- 
closed, the light is again at once extinguished. 
It may be observed that the largest of these 
organs is in this species situated just under | 
the eye, so that the fish is actually provided 
with a bull’s eye lantern. In other cases the 
light may rather serve as a defence, some 
having, as, for instance, in the genus Scope- 
lus, a pair of large ones in the tail, so that 
“a strong ray of light shot forth from the 
stern-chaser may dazzle and frighten an 
enemy.” ; 
In other cases they appear to serve as” 
1 Gunther, History of Fishes. 
