88 
Fresh News on Earthworms. 
^February, 
3. It distributes the fertilising matter in the subsoil, and 
renders it more accessible to the uniform adbion of air 
and moisture, thus aiding in the liberation of the 
mineral constituents of plant-food. 
It is well known that soils, and especially subsoils, may 
contain a large proportion of the elements necessary for the 
nutrition of plants, but in such a state as to be practically 
unavailable. To render them assimilable they have to be 
decomposed by the aCtion of the carbonic acid contained in 
the atmosphere, and by water. These agents are admitted 
into the soil by the mechanical operations of agriculture, and 
probably even to a greater extent by the unceasing work of 
the earthworms. Hence Prof. Hensen makes the startling 
— butwe believe perfectly justifiable — assertion, thatchemical 
analysis of a subsoil gives no sufficient insight into its fertility 
if the number of worm-holes are not also taken into due 
consideration. 
As regards the quantity of earthworms living and boring 
in the soil, we do not find any absolute agreement among 
different authorities. This is merely what might be expected 
from the differences of soil, climate, season, and other con- 
ditions. Hensen calculates per acre of arable soil 110 lbs. 
of worms, weighed with their intestines emptied of soil. 
H. von Lengerke takes a considerably higher estimate. In 
an acre of meadow-land he found 176 lbs. of L. terrestris and 
550 lbs. of L. communis , or in all 720 lbs. of worms. In 
strange contrast with these figures would be the number 
discoverable in suburban gardens around London, which in 
barrenness are probably unsurpassed. 
Prof. P. E. Muller has studied the behaviour of worms in 
woodland soils, especially in the beech-woods, in which 
Denmark is — or perhaps rather was — so rich. The beech 
tree flourishes in the mild beech-humus, but dies off on the 
beech-moors, — that is, as we understand the author, on soils 
where beech-woods have once existed. In the former class 
of soils earthworms live in plenty, whilst in the “ beech- 
moors ” they are entirely wanting, and indeed animal life is 
altogether very sparingly represented. 
On mossy, heathery, and boggy soils, worms are not nu- 
merous in most parts of England. According to Mr. Kina- 
han the same rule holds good in Ireland. 
Like Prof. Hensen, but unlike Darwin, P. E. Muller is of 
opinion that the earthworm is not nourished by the soil. 
It eats the soil, indeed, but as a method of opening its 
tubes and removing the excavated material. Any 
