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tank to tank. The method o£ aeration consists in forcing 
air by means of a hand pump into compression cylinders, 
whence it is distributed along slender tubes to the different 
tanks. Each distribution tube is connected with a filter 
candle through which the air is driven into the tank in a 
cloud of small bubbles. The air pump is worked at intervals, 
both by day and by night, for experience has shown that if 
the supply of air were cut off for a comparatively short time 
all the inhabitants of the tanks would perish. The fish are 
living permanently under conditions of overcrowding which 
could only be found temporarily in the open sea. Similarly, 
in the case of a building crowded with human beings, a 
proper supply of fresh air must be admitted or the people 
will suffer. The water which has circulated through the 
tanks can, if desired, be brought back to the filter-beds, and, 
after purification, used a second time. 
“ Nearly all the exhibited specimens have been captured 
within a few miles of the Aquarium. The fish are caught 
in ordinary fishing nets, many of them in the sheltered 
waters of Madras harbour, but in the absence of steam 
trawlers, or of boats fitted with tanks, considerable difficulty 
is experienced in bringing them alive to the Aquarium. 
Indeed, for every fish safely placed in a tank a great many 
die in transit, as a result of accident, exposure to the sun, 
or want of air. Curiously enough, one of the commonest 
causes of fatality exists in injuries to the eyes. The fish, 
on being removed from their natural element, often dash 
wildly against the sides of the tub or other vessel in which 
they are temporarily placed, with the result that their eyes, 
which are unprotected by eyelids, frequently get damaged. 
Once the fish are fairly established in their new quarters the 
chief difficulty has been overcome, and, accidents excepted, 
they are likely to live a reasonable period of time. At the 
time of writing (March, 1912) there are several fishes in the 
Aquarium which have been in residence for over two years. 
“ The fish and turtles are fed once daily, their food consist- 
ing chiefly of choj)ped-up fish, crustaceans such as a crab 
found commonly in the sand within the surf zone [Hippa 
aslatica^ the “gilly poochi”), and sand-worms. 
