Saturday, May 30, 2009
56. The Action of Worms, as per the Notes of Charles Darwin (Chinese Bells of Great Antiquity 千古绝响曾侯乙编钟之声)
The accumulation of rubbish on the sites of great cities independent of the action of worms — The burial of a Roman villa at Abinger — The floors and walls penetrated by worms — Subsidence of a modern pavement — The buried pavement at Beaulieu Abbey — Roman villas at Chedworth and Brading — The remains of the Roman town at Silchester — The nature of the débris by which the remains are covered — The penetration of the tesselated floors and walls by worms — Subsidence of the floors — Thickness of the mould — The old Roman city of Wroxeter — Thickness of the mould — Depth of the foundations of some of the buildings — Conclusion.
13 September; soft wet weather. The mouths of the burrows were re-opened, or castings were ejected, at 31 points; these were all defaced.
14 September; 34 fresh holes or castings all defaced.
15 September; 44 fresh holes, only 5 castings; all defaced./
18 September; 43 fresh holes, 8 castings; all defaced.
The number of castings on the surrounding fields was now very large.
19 September; 40 holes, 8 castings; all defaced.
22 September; 43 holes, only a few fresh castings; all defaced.
23 September; 44 holes, 8 castings.
25 September; 50 holes, no record of the number of castings.
13 October; 61 holes, no record of the number of castings.
...that we have here evidence of two/fires, separated by an interval of time, during which the 6 inches of 'mortar and concrete/with broken tiles' was accumulated. Beneath one of the layers of charred wood, a valuable relic, a bronze eagle, was found; and this shows that the soldiers must have deserted the place in a panic. Owing to the death of Mr Joyce, I have not been able to ascertain beneath which of the two layers the eagle was found. The bed of rubble overlying the undisturbed gravel originally formed, as I suppose, the floor, for it stands on a level with that of a corridor, outside the walls of the Hall; but the corridor is not shown in the section as here given. The vegetable mould was 16 inches thick in the thickest part; and the depth from the surface of the field, clothed with herbage,...
In almost all the rooms the pavement has/sunk considerably, especially towards the middle; and this is shown in the three following sections. The measurements were made by stretching a string tightly and horizontally over the floor. The section, Fig. 13, was taken from north to south across a room, 18 feet 4 inches in length, with a nearly perfect pavement, next to the 'Red Wooden Hut'.
The nature of the beds immediately beneath the vegetable mould in some of the sections is rather perplexing.
Evidence of the amount of denudation which the land has undergone — Subaerial denudation — The deposition of dust — Vegetable mould, its dark colour and fine texture largely due to the action of worms — The disintegration of rocks by the humus acids — Similar acids apparently generated within the bodies of worms — The action of these acids facilitated by the continued movement of the particles of earth — A thick bed of mould checks the disintegration of the underlying soil and rocks. Particles of stone worn or triturated in the gizzards of worms — Swallowed stones serve as millstones — The levigated state of the castings — Fragments of brick in the castings over ancient buildings well rounded. The triturating power of worms not quite insignifcant under a geological point of view.
Not only do worms aid indirectly in the chemical disintegration of rocks, but there is good reason to believe that they likewise act in a direct and mechanical manner on the smaller particles. All the species which swallow earth are furnished with gizzards; and these are lined with so thick a chitinous membrane, that Perrier speaks of it, Archives de Zoolog. expér., vol. iii, 1874, p. 409. †13 as 'une véritable armature'.
THE DENUDATION OF THE LAND — continued
Abinger, Roman villa at, 178
castings from Roman villa, with rounded particles, 253
Acids of human, action on rocks, 240
Africa, dust from, 235
Air, currents of, worms sensitive to, 28
Amount of earth brought to the surface by worms, 129
Ants, intelligence of, 93
Archiac, D', criticisms on my views, 4
As the foundations of the walls generally lie at a considerable depth, they will either have not subsided at all through the undermining action of worms, or they will have subsided much less than the floor. This latter result would follow from worms not often working deep down beneath the foundations; but more especially from the walls not yielding when penetrated by worms, whereas the successively formed burrows in a mass of earth, equal to one of the walls in depth and thickness, would have collapsed many times since the desertion of the ruins, and would consequently have shrunk or subsided.