The Book of Household Management by Mrs. Beeton

found in their own element. They are mostly carnivorous, though they seize upon almost anything that comes in their way: they even devour their own offspring, and manifest a particular predilection for all living creatures. Those, to which Nature has meted out mouths of the greatest capacity, would seem to pursue everything with life, and frequently engage in fierce conflicts with their prey. The animal with the largest mouth is usually the victor; and he has no sooner conquered his foe than he devours him. Innumerable shoals of one species pursue those of another, with a ferocity which draws them from the pole to the equator, through all the varying temperatures and depths of their boundless domain. In these pursuits a scene of universal violence is the result; and many species must have become extinct, had not Nature accurately proportioned the means of escape, the production, and the numbers, to the extent and variety of the danger to which they are exposed. Hence the smaller species are not only more numerous, but more productive than the larger; whilst their instinct leads them in search of food and safety near the shores, where, from the shallowness of the waters, many of their foes are unable to follow them.