Page:The aquarium - an unveiling of the wonders of the deep sea.djvu/147

106 Thus there were nearly a hundred animals in this Tank; a number which I found far too great; for though they did not crowd the vessel at all apparently, nor seem disproportioned to the space they occupied, it became evident that the exhaustion of the oxygen of the water went on more rapidly than it could be renewed, either by the evolution from the living plants, or by the combination with this of artificial aeration, by allowing two or three gallons a day to drip from a vessel suspended over the Tank at the height of about four feet.

For about ten days the animals appeared pretty well; a little diminution occuring from the assaults of the predatory species on their weaker fellows. Then