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ANALYSES OF BOOKS. 
The Formation of Vegetable Mould through the Action of Earth- 
Worms, with Observations on their Habits. By Charles 
Darwin, LL.D., F.R.S. London : John Murray. 
Many persons will probably consider the work before us un- 
Darwinian. It contains, indeed, no reference to the origin or the 
transformation of organic species, or to the theory with which 
the name of our great English naturalist will be for ever con- 
nected. But it is characteristically Darwinian as summing up 
the effects of a continually recurrent cause, each of whose mani- 
festations may be feeble, whilst their total result is mighty. The 
ability thus to trace the working of agencies is one of the most 
prominent features of the author’s mind. Another characteristic 
of the writer is the patience and perseverance with which, in this 
as well as in his other researches, his ideas are elaborated and 
tested prior to final publication. More than forty years ago Mr. 
Darwin read before the Geological Society a short paper on the 
formation of the so-called vegetable mould. He referred to the 
fact that ashes, burnt marl, &c., which have been spread over the 
surface of meadows, gradually disappear from view, and in the 
course of a few years may be found in a layer at the depth of 
some inches beneath the turf. This phenomenon, which farmers 
often ascribe to some “ kind of alacrity in sinking ” possessed 
by bones, marl, lime, and other materials spread upon the land, 
was traced by the author, at the suggestion of his friend Mr. 
Wedgwood, to the agency of earth-worms. The theory was 
opposed by M. d’Archiac, Mr. Fish, and others ; but Mr. Darwin 
has not merely fully proved it by a series of prolonged and care- 
ful measurements, in which his sons and several of his friends 
have taken a part, but he has further shown that these humble 
creatures are geological agents of no small importance, aiding in 
the disintegration of rocks, in the denudation of the land, as well 
as in the preparation of the soil for the growth of plants. 
The inquiry necessarily involved a careful examination of the 
habits, powers, and faculties of the earth-worm. Everyone 
knows that this little animal lives in tubular burrows in the 
earth, which it rarely leaves except before evening; that it travels 
in the night, especially in damp, rainy weather, leaving long 
tracks in the mud and sand. Everyone must also have noticed 
their so-called “ castings,” — small heaps of earth which they 
bring up to the surface of lawns, meadows, &c. The worm in 
making its burrows pushes the soil partly aside, and eats the 
