186 MARVELS OF FISH LIFE 
takes up more oxygen. Further, if the water is so 
shallow that the fish disturbs the surface as he swims 
about, the absorption of oxygen from the air is materially 
assisted. Personally, I keep fish in a tank with water 
splashing on to the surface from a considerable height, 
for at home my fish photography is uncertain, and it 
is often a week or more before I can attend to the 
specimen. 
In passing, let me refer to the keeping of fish in 
bowls and small aquaria. I do not believe anybody 
is intentionally callous to the sufferings of beasts, bird, 
or fish. But in our ignorance there is no doubt we 
inflict much unnecessary pain on our pets. Fish in 
natural environments depend for a healthy existence 
and comfort on abundance of food, oxygen, and a sub- 
dued light. Yet how many fish are kept in a glass 
bowl, the bowl placed in the bright light of a window, 
the water seldom if ever aerated, and the fish occa- 
sionally offered a little vermicelli. These fish are ex- 
pected to be interesting. It would be as reasonable 
to keep an accepted wit in a dark, badly ventilated 
cellar of your house, feed him occasionally on a plate 
of worms, and expect him to bubble with good humour 
when visited by yourself and your friends. 
I have referred to the photography of fish in natural 
environments and in tanks; with the latter method I 
would like to compare the photography of fish in the 
pond. 
Photography in a glass tank is undoubtedly the best 
