Still, as size is only comparative, the rule that holds good with a small animal may hold equally good with a large one. It is my lot to walk very often upon the banks of the Thames. It is a charming walk at high water, but at low water there is too much odoriferous mud, and there are too many dead dogs and cats to make it an agreeable resort, except for enthusiastic entomologists, who seem to swarm in this neighbourhood.
Scarcely has such a carcass been stranded than it is beset by Burying-beetles of various kinds. Hundreds upon hundreds can be shaken out of the corpse of a dog or cat, and, before the next tide has come up, there is scarcely any flesh left on the bones, it having been dug into the earth by the Burying-beetles.
Then there is that wonderful family of Scarabæus-beetles, which do us invaluable service as scavengers and agriculturists. They follow the path of the caravans, and effectively cleanse the course which has been traversed. Even man is obliged to utilise as fuel the droppings of the horses, cows, and camels; but the Scarabæus goes further, collecting all that man does not need, and burying it in the earth.
The instinct of the female Scarabæus urges it to gather together the rejecta, to form them into balls, placing an egg in the middle of each ball, and to bury them in the ground. Thus a double object is attained, the offensive substances being removed from the surface of the ground, where they do harm, and being transferred below the surface, where they do good.
Even the curious instinct of the dog, which leads it to bury bones, &c., which it cannot consume, and which it often forgets, if well fed, leaves them to be consumed by the all-absorbing earth.
It is evident that, in the end, the earth must receive back again that which has been taken from it. If, for example, we follow the present most wasteful plan of drainage, and fling into rivers everything which ought to be utilised on land, it only gets into the sea in the end, and in the course of years is decomposed, and returns to the earth in the form of gases. Meanwhile, however, we have robbed the locality, deprived it of the nourishment which it required, and forced ourselves to supply it elsewhere at a costly rate.
So runs the cycle of creation. Sooner or later, Nature will have her way, and the more we help her, the better it will be for us.
Of course I do not mean to condemn Drainage, which is an absolute necessity in agriculture, and a matter of life and death in households. But, when rightly conducted, it only signifies that water is removed from a spot which is overstocked with moisture to one where it is needed. Wet clay lands, for example, which were unproductive in point of crops, and injurious in point of human health, have been converted by judicious drainage into fertile and healthy grounds.
This, as it will be seen, is a very different business from removing from the soil the elements which rightly belong to it, and which sooner or later, in some form or another, it will claim and recapture.