12 Big Game Fishes 
regions are adapted by nature to the peculiar 
conditions. The pressure where they live is 
sufficient to powder glass; at the surface it is 
fifteen pounds per square inch, but increases 
rapidly, so that at a mile below the surface it 
is almost beyond comprehension. 
To overcome this the skeleton of deep-sea 
forms is cavernous, porous, and the water ap- 
pears to circulate through them as through a 
sponge, and although fierce and carnivorous 
creatures, they are so fragile out of water that 
when taken from the nets they almost drop in 
pieces. The most remarkable feature of these 
fishes and many surface forms is their phos- 
phorescence, many having illuminating organs 
—torches —of one or more colors, which con- 
stitute a part of the illumination of the deep sea, 
and serve possibly as a signal language by 
which the sexes are attracted, or predaceous 
forms lure their prey. I have seen a tuna come 
up at night, having a train of light several feet 
in length, but this was due to the luminous ani- 
mals in the water—the peridinium, salpa, and 
others. 
The game fishes available to the rod fisher- 
man constitute a small proportion of the fishes, 
