The vast subject which I have thus lightly skimmed is not without interest, again, from its human implications.  Savages as a rule produce enormous families; but then, the infant mortality in savage tribes is proportionally great.  Among civilized races, families are smaller, and deaths in infancy are far less numerous.  The higher the class or the natural grade of a stock, the larger as a rule the proportion of children safely reared to the adult age.  The goal towards which humanity is slowly moving would thus seem to be one where families in most cases will be relatively small—­perhaps not more on an average than three to a household—­but where most or all of the children brought into the world will be safely reared to full maturity.  This is already becoming the rule in certain favored ranks of European society.

[Illustration:  TADPOLES AND YOUNG FROG.]

HOW ANIMALS SPEND THE WINTER

(FROM GLEANINGS FROM NATURE.)[2]

BY W. S. BLATCHLEY.

[2] “Popular Science Monthly,” February, 1897.  Copyright by William Stanley Blatchley, 1899.

[Illustration:  A COCOON.]

One of the greatest problems which each of the living forms about us has had to solve, during the years of its existence on earth, is how best to perpetuate its kind during that cold season which once each year, in our temperate zone, is bound to come.  Many are the solutions to this problem.  Each form of life has, as it were, solved it best to suit its own peculiar case, and to the earnest student of Nature there is nothing more interesting than to pry into these solutions and note how varied, strange, and wonderful they are.

To fully appreciate some of the facts mentioned below it must be borne in mind that there is no such thing as “spontaneous generation” of life.  Every cell is the offspring of a pre-existing cell.  Nothing but a living thing can produce a living thing.  Hence every weed that next season will spring up and provoke the farmer’s ire, and every insect which will then make life almost intolerable for man or beast, exists throughout the winter in some form....

Beginning with the earth-worms and their kindred, we find that at the approach of winter they burrow deep down where the icy breath of the frost never reaches, and there they live, during the cold season, a life of comparative quiet.  That they are exceedingly sensitive to warmth, however, may be proven by the fact that when a warm rain comes some night in February or March, thawing out the crust of the earth, the next morning reveals in our dooryards the mouths of hundreds of the pits or burrows of these primitive tillers of the soil, each surrounded by a little pile of pellets, the castings of the active artisans of the pits during the night before.

If we will get up before dawn on such a morning we can find the worms crawling actively about over the surface of the ground, but when the first signs of day appear they seek once more their protective burrows, and only an occasional belated individual serves as a breakfast for the early birds.