played a very important part in the competition for food supplies.
The life stories of different creatures are by no means equally easy or equally difficult—generally it is towards the latter quality that the complicated history leads us. Some animals have more enemies than others, some pass through stages which expose them to more varied dangers; indeed, the more complex the life before reaching maturity the less the chance of attaining it. But there is compensation, or none of the weaker brethren could survive; the creature with a simple, shadowed life produces few young, and the required number, a fair proportion of the whole, come to their own; the one with many foes and a long and precarious youth presents the world with an overflowing family. The cod with its two to five million eggs might mourn the death of five million infants and leave its fortune to two and only two; the rest, if it is any satisfaction to it to know, have probably gone to improve the stock of other species, not excluding the cod itself; indeed, it is not at all unlikely that many cod thrive on their own offspring.
The guillemot, on the other hand, a bird which no doubt assists in keeping down the surplus population of the cod, has but to lose a few, perhaps two or three, out of its annual output of one big egg. The mortality of the species is small, yet when we find the storm-battered bodies of this pelagic species thick along the tide line we think more seriously of it than the massacre of the millions of possible cods. Suppose that for a few seasons the cod should have a dearth of enemies, say if some epidemic or other catastrophe overtook the normal feeders on its pelagic eggs and larvae, and a few thousands from each we came to maturity; where would the food be in the overstocked seas for the vast army of hungry cods? Nature, by the simple method of starving the unwanted,
