A1839    Review:     Anon. 1881. [Review of Earthworms]. Darwin on earth-worm. Observer (20 November): 3.   Text   PDF

The Complete Work of Charles Darwin Online [page] 3 DARWIN ON EARTH-WORMS.* To most persons, the topic of ''worms,'' must appear decidedly uninteresting, if not in some respects unsavoury. There are, of course, worms and worms; but amongst backbone-less things, the whole worm-race may be said to exist only for the delectation of people who, like zoologists and botanists, can find delight in a sponge, or who may in a sense be said to live up to a fungus. Yet every yule has ita exceptions, and

F1361    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. fifth thousand (corrected), and with textual changes. London: John Murray.   Text   Image   PDF

surface, is a question which has probably never occurred to them.* The Sinking of great Stones through the Action of Worms. When a stone of large size and of irregular shape is left on the surface of the ground, it rests, of course, on the more protuberant parts; but worms soon fill up with their castings all the hollow spaces on the lower side; for, as Hensen remarks, they like the shelter of stones. As soon as the hollows are filled up, the worms eject the earth which they have swallowed

A1302    Review:     Anon. 1881. [Review of Earthworms] Boston Post (25 November): 3.   Text   PDF

The Complete Work of Charles Darwin Online [page] 3 The Formation of Vegetable Mould through the Action of Worms, with Observations on their Habits, by Charles Darwin, LL.D., F.R.S., is scientific work, the character of which can be judged very accurately from the title. It will be seen that the subject of the work is not of absorbing interest to the average citizen, but to the scientist it is a matter of considerable importance, and anything from the pen of Prof. Darwin calls for careful

CUL-DAR158.1-76    Note:    [1838.08.00--1881]   Personal ' Journal' 1809-1881   Text   Image   PDF

Journal.6 Paper on worms. forming mould. 7 1 Notebook B. 2 Darwin 1837. 3 Darwin 1837. 4 Zoology. 5 Geology. 6 Journal of researches. 7 Darwin 1838. [13v] [1838

F1361    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. fifth thousand (corrected), and with textual changes. London: John Murray.   Text   Image   PDF

Worms, contents of intestines, acid, 51 their castings, acid, 52 power of suction, 56 plugging up their burrows, 58 intelligence of, 64 formation of their burrows, 98 number of, living in a given area, 159 penetrating ancient walls, 188, 209 gizzards of, and the trituration of the contained stones, 246 prefer to live in fine earth, 291 Wright, Mr., on the age of Wroxeter, 221 Wroxeter, old Roman town of, 221 Zincke, Rev. F. B., on celts found at a depth of three feet, 146. [page break

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

I became interested in them, and wished to learn how far they acted consciously, and how much mental power they displayed. I was the more desirous to learn something on this head, as few observations of this kind have been made, as far as I know, on animals so low in the scale of organization and so poorly provided with sense-organs, as are earth-worms. In the year 1837, a short paper was read by me before the Geological Society of London,* On the Formation of Mould, in which it was shown that

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

In the year 1869, Mr. Fish* rejected my conclusions with respect to the part which worms have played in the formation of vegetable mould, merely on account of their assumed incapacity to do so much work. He remarks that considering their weakness and their size, the work they are represented to have accomplished is stupendous. Here we have an instance of that inability to sum up the effects of a continually recurrent cause, which has often retarded the progress of science, as formerly in the

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

Eisen;* but two of these rarely burrow in the ground, and one inhabits very wet places or even lives under the water. We are here concerned only with the kinds which bring up earth to the surface in the form of castings. Hoffmeister says that the species in Germany are not well known, but gives the same number as Eisen, together with some strongly marked varieties. Earth-worms abound in England in many different stations. Their castings may be seen in extraordinary numbers on commons and chalk

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

but on the more level parts, where a bed of fine earth had been washed down from the steeper parts and had accumulated to a thickness of a few inches, worm-castings abounded. These spots seemed to be overstocked with worms, so that they had been compelled to spread to a distance of a few feet from the grassy paths, and here their castings had been thrown up among the heath; but beyond this limit, not a single casting could be found. A layer, though a thin one, of fine earth, which probably

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

extremely sensitive to vibrations in any solid object. When the pots containing two worms which had remained quite indifferent to the sound of the piano, were placed on this instrument, and the note C in the bass clef was struck, both instantly retreated into their burrows. After a time they emerged, and when G above the line in the treble clef was struck they again retreated. Under similar circumstances on another night one worm dashed into its burrow on a very high note being struck only

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

means odoriferous and much-coveted kinds of food. It may be presumed that all animals which feed on various substances possess the sense of taste, and this is certainly the case with worms. Cabbage-leaves are much liked by worms; and it appears that they can distinguish between different varieties; but this may perhaps be owing to differences in their texture. On eleven occasions pieces of the fresh leaves of a common green variety and of the red variety used for pickling were given them, and

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

likewise petioles, peduncles and decayed flowers. But they will also consume fresh leaves, as I have found by repeated trials. According to Morren* they will eat particles of sugar and liquorice; and the worms which I kept drew many bits of dry starch into their burrows, and a large bit had its angles well rounded by the fluid poured out of their mouths. But as they often drag particles of soft stone, such as of chalk, into their burrows, I feel some doubt whether the starch was used as food

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

kind is found in the intestines of worms. As the leaves which are dragged into the burrows are often dry and shrivelled, it is indispensable for their disintegration by the unarmed mouths of worms that they should first be moistened and softened; and fresh leaves, however soft and tender they may be, are similarly treated, probably from habit. The result is that they are partially digested before they are taken into the alimentary canal. I am not aware of any other case of extra-stomachal

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

with fine ferruginous sand, it was manifest that the oxide of iron, with which the grains of silex were coated, had been dissolved and removed from them in the castings. The digestive fluid of worms resembles in its action, as already stated, the pancreatic secretion of the higher animals; and in these latter, pancreatic digestion is essentially alkaline; the action will not take place unless some alkali be present; and the activity of an alkaline juice is arrested by acidification, and

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

, by worms having acquired the habit of generally drawing in leaves by their tips and thus avoiding the foot-stalk. For the basal margin of the blade in many kinds of leaves forms a large angle with the foot-stalk; and if such a leaf were drawn in by the foot-stalk, the basal margin would come abruptly into contact with the ground on each side of the burrow, and would render the drawing in of the leaf very difficult. Nevertheless worms break through their habit of avoiding the footstalk, if this

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

are regularly drawn into the mouths of worm-burrows. These leaves consist of two needles, which are of considerable length in the two first and short in the last named species, and are united to a common base; and it is by this part that they are almost invariably drawn into the burrows. I have seen only two or at most three exceptions to this rule with worms in a state of nature. As the sharply pointed needles diverge a little, and as several leaves are drawn into the same burrow, each tuft

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

cent. by the apex. This anomaly was however readily explained as soon as the thick basal part was examined; for in 78 out of 103 petioles, this part had been gnawed by worms, just above the horse-shoe shaped articulation. In most cases there could be no mistake about the gnawing; for ungnawed petioles which were examined after being exposed to the weather for eight additional weeks had not become more disintegrated or decayed near the base than elsewhere. It is thus evident that the thick

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

33 per cent, by the base. In five cases, two triangles were drawn into the same burrow. It may be suggested with much apparent probability that so large a proportion of the triangles were drawn in by the apex, not from the worms having selected this end as the most convenient for the purpose, but from having first tried in other ways and failed. This notion was countenanced by the manner in which worms in confinement were seen to drag about and drop the triangles; but then they were working

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

25 16 of the narrow ones alone 65 14 21 If we consider these several cases, we can hardly escape from the conclusion that worms show some degree of intelligence in their manner of plugging up their burrows. Each particular object is seized in too uniform a manner, and from causes which we can generally understand, for the result to be attributed to mere chance. That every object has not been drawn in by its pointed end, may be accounted for by labour having been saved through some being

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

. Castings of a similar nature continued to be ejected from the burrow during the whole of the following day. As doubts have been expressed by some writers whether worms ever swallow earth solely for the sake of making their burrows, some additional cases may be given. A mass of fine reddish sand, 23 inches in thickness, left on the ground for nearly two years, had been penetrated in many places by worms; and their castings consisted partly of the reddish sand and partly of black earth brought up from

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

with them, mingled with fragments of other kinds of leaves, drawn in to a depth of 4 or 5 inches. Worms often remain, as formerly stated, for a long time close to the mouths of their burrows, apparently for warmth; and the basket-like structures formed of leaves would keep their bodies from coming into close contact with the cold damp earth. That they habitually rested on the pine-leaves, was rendered probable by their clean and almost polished surfaces. The burrows which run far down into the

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

sandy earth of which they were formed still cohered with considerable tenacity. The late Mr. John Scott of the Botanic Gardens near Calcutta made many observations for me on worms living under the hot and humid climate of Bengal. The castings abound almost everywhere, in jungles and in the open ground, to a greater degree, as he thinks, than in England. After the water has subsided from the flooded rice-fields, the whole surface very soon becomes studded with castings a fact which much

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

few bits of rock, the largest of which was only 15 inch in diameter. Dr. King saw in Ceylon a worm about 2 feet in length and inch in diameter; and he was told that it was a very common species during the wet season. These worms must throw up castings at least as large as those on the Nilgiri Mountains; but Dr. King saw none during his short visit to Ceylon. Sufficient facts have now been given, showing that worms do much work in bringing up fine earth to the surface in most or all parts of the

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

average annual rate of from 2 to 22 of an inch. But in this district when a ploughed field is first laid down in grass, the mould accumulates at a much slower rate. The rate, also, must become very much slower after a bed of mould, several inches in thickness, has been formed; for the worms then live chiefly near the surface, and burrow down to a greater depth so as to bring up fresh earth from below, only during the winter when the weather is very cold (at which time worms were found in this field at

F1357    Book:     Darwin, C. R. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. London: John Murray.   Text   Image   PDF

to the brick-rubbish beneath the more protuberant parts having been undermined by worms. At this rate the upper surface of the stone, if it had been left undisturbed, would have sunk to the general level of the field in 247 years; but before this could have occurred, some earth would have been washed down by heavy rain from the castings on the raised border of turf over the upper surface of the stone. The second stone was larger than the one just described, viz., 67 inches in length, 39 in