"But if the vicissitudes of climate are fraught with suffering, so are the vicissitudes of age. The infancy of many animals is as helpless as babyhood. Few hired nurses, it is true, are so patient, so provident, so watchful, so untiring in care, as the dams, feathered or furred, who, in nest or lair, watch over their young. But then the lives of these guardians are terribly precarious, and innumerable are the orphans of the animal world."