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MR. DARWIN ON WORMS.

MR. DARWIN'S new work, "The Formation of Vegetable Mould through the Action of Worms, with Observations on their Habits," is devoted to a minute yet extremely interesting account of the anatomy and habits of the lowly earthworm, and the wonderful effects which its taste for eating dirt and voiding it again, "acting through long ages," has produced on the surface of the earth. From this point of view the book has some slight bearings on the "theory" to the support of which all of his researches tend more or less. In every other respect it is simply a popular treatise on a common object of almost every country in the world. Nor, indeed, is the subject new. A score of works and "papers" have been written on the earthworm, and forty-four years ago Mr. Darwin himself published an outline of the observations of which the present work may be considered as the expansion.

In 1837 he showed that worms by swallowing earth, in order to extract from it the organic nutriment which it contains, passing it through their intestines, and then voiding it in the little castings so familiar to every one, play an important part in the natural cultivation of the soil. In time the stony surface of the ground is covered with a layer of virgin earth, brought up from a depth from three to eight feet; or if the ground is, as in forests, littered with leaves, aide in forming a rich mould peculiarly suited for the growth of vegetable life. In rainy weather the finely-levigated castings flow down any moderate slope, so that there is a continual renewal of the surface. In this manner great results are accomplished for the benefit of the agricultural interest. But Mr. Darwin is even more enthusiastic over the gratitude antiquaries owe to the despised worm. Coins, gold ornaments, stone implements, &c., if dropped on the surface of the ground will infallibly be buried by the castings of the worms in a few years, and will thus be safely preserved until the land at some future period us turned up. The tesselated pavement of Abinger, in Surrey, was covered with at least fourteen inches of worm castings. The remains of a Roman villa at Chedworth, in Gloucestershire, were concealed under thirty-eight inches of similar soil; and the fine villa recently discovered at Brading, in the Isle of Wight, had been buried by worms to the depth of from three to four feet, the floor having gradually sank as the earth which the annelids piled up was removed by them. In like manner─not to heap one feet above another─the Roman towns of Silchester, in Hampshire, and Uriconium (Wroxeter), in Shropshire, have experienced the kindly attention of the worms; and among other instance of a like nature, one of the fallen blocks at Stonehenge has sunk considerably below the level of the surrounding ground through the same agency. "It is a marvellous reflection," Mr. Darwin remarks in closing his volume, "that the whole of the superficial mould over any turf-covered expanse has passed, and will pass again every few years, through the bodies of worms. The plough is one of the most ancient and most valuable of man's inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earthworms. It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures."