Search Results - The Complete Work of Charles Darwin Online

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

HABITS OF WORMS. CHAP. II. as well as the seeds, are carried down from the surface by being swallowed; for a surprising number of glass beads, bits of tile and of glass were certainly thus carried down by worms kept in pots; but some may have been carried down within their mouths. The sole conjecture which I can form why worms line their winter-quarters with little stones and seeds, is to prevent their closely coiled-up bodies from coming into close contact with the surrounding cold soil; and

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

HABITS OF WORMS. CHAP. II. the movements were twice as great. These observations were made by my son Horace, who will hereafter publish an account of the movements of this stone during successive wet and dry seasons, and of the effects of its being undermined by worms. Now when the ground swells, if it be penetrated by cylindrical holes, such as worm-burrows, their walls will tend to yield and be pressed inwards; and the yielding will be greater in the deeper parts (supposing the whole to be

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

CHAP. II. THEIR WIDE DISTRIBUTION. abound in Iceland, and are known to exist in the West Indies, St. Helena, Madagascar, New Caledonia and Tahiti. In the Antarctic regions, worms from Kerguelen Land have been described by Ray Lankester; and I found them in the Falkland Islands. How they reach such isolated islands is at present quite unknown. They are easily killed by salt-water, and it does not appear probable that young worms or their egg-capsules could be carried in earth adhering to the

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

HABITS OF WORMS. CHAP. II. three cubic centimeters. They were, therefore, of small size in comparison with those often found in England; for six large castings from a field near my house averaged 16 cubic centimeters. Several species of earth-worms are common in St. Catharina in South Brazil, and Fritz Müller informs me that in most parts of the forests and pasture-lands, the whole soil, to a depth of a quarter of a metre, looks as if it had passed repeatedly through the intestines of earth

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

HABITS OF WORMS. CHAP. II. largest received by me was 3 1/2 inches in height and 1.35 inch in diameter; another was only 3/4 inch in diameter and 2 3/4 in height. Fig. 3 A tower-like casting, probably ejected by a species of Perichæta from the Botanic Garden, Calcutta: of natural size, engraved from a photograph. [page] 12

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

HABITS OF WORMS. CHAP. II. of their having been found at 4 feet. Within the forests, fresh castings may be found even during the hot season. The worms in the Botanic garden, during the cool and dry season, draw many leaves and little sticks into the mouths of their burrows, like our English worms; but they rarely act in this manner during the rainy season. Mr. Scott saw worm-castings on the lofty mountains of Sikkim in North India. In South India Dr. King found in one place, on the plateau of

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

CHAPTER III. THE AMOUNT OF FIXE EARTH BROUGHT UP BY WORMS TO THE SURFACE. Rate at which various objects strewed on the surface of grass-fields are covered up by the castings of worms —The burial of a paved path —The slow subsidence of great stones left on the surface—The number of worms which live within a given space —The weight of earth ejected from a burrow, and from all the burrows within a given space —The thickness of the layer of mould which the castings on a given space would form

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

CHAP. III. BROUGHT UP BY WORMS. beneath the general level of the field. It should, however, be observed that the thickness of the blackish sandy soil, which had been thrown up by the worms above the marl-fragments in the course of 32 1/2 years, would have measured less than 15 inches, if the field had always remained as pasture, for the soil would in this case have been much more compact. The fragments of marl almost rested on an undisturbed sub-stratum of white sand with quartz pebbles; and

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

sufficient to account for its having sunk about 2 inches into the ground; more especially if we bear in mind that a good deal of the finest earth would have been washed by heavy rain from the castings ejected on the sloping border down to the level of the field. Some fresh castings were seen close to the stone. Nevertheless, on digging a large hole to a depth of 18 inches where the stone had lain, only two worms and a few burrows were seen, although the soil was damp and seemed favourable for worms

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

earth daily ejected by worms, Hensen found that it amounted, in the case of some worms which he kept in confinement, and which he appears to have fed with leaves, to only 0.5 gram, or less than 8 grains per diem. But a very much larger amount must be ejected by worms in their natural state, at the periods when they consume earth as food instead of leaves, and when they are making deep burrows. This is rendered almost certain by the following weights of the castings thrown up at the mouths of

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

CHAP. III. BROUGHT UP BY WORMS. was shaded during part of the day by trees. It had been formed at least a century ago by a great accumulation of small and large fragments of sandstone, together with some sandy earth, rammed down level. It is probable that it was at first protected by being covered with turf. This terrace, judging from the number of castings on it, was rather unfavourable for the existence of worms, in comparison with the neighbouring fields and an upper terrace. It was indeed

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

CHAP. III. ANNUALLY ACCUMULATED. lower level some of the finest earth which is continually being brought to the surface by worms. How great a thickness vegetable mould ever attains, I have not had good opportunities for observing; but in the next chapter, when we consider the burial of ancient buildings, some facts will be given on this head. In the two last chapters we shall see that the soil is actually increased, though only to a small degree, through the agency of worms; but their chief

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

after the floor had been cleared. On the previous night there had been some heavy rain, which washed the surface clean, and now the mouths of forty burrows were counted. Parts of the concrete were seen to be solid, and had never been penetrated by worms, and here the rain-water lodged. Sept. 5th. —Tracks of worms, made during the previous night, could be seen on the surface of the floor, and five or six vermiform castings had been thrown up. These were defaced. Sept. 12th. —During the last six

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

, we may feel sure, would be filled up by the worms with their castings, as soon as they were able to penetrate the wall. Bain-water, oozing down the burrows would also carry fine dark-coloured particles into every crevice. Mr. Joyce was at first very sceptical about the amount of work which I attributed to worms; but he ends his notes with reference to the last-mentioned wall by saying, This case caused me more surprise and brought more conviction to me than any other. I should have said, and did

33%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

apparently serves to neutralise the acids thus generated; for the digestive fluid of worms will not act unless it be alkaline. As the contents of the upper part of their intestines are acid, the acidity can hardly be due to the presence of uric acid. We may therefore conclude that the acids in the alimentary canal of worms are formed during the digestive process; and that probably they are nearly of the same nature as those in ordinary mould or humus. The latter are well known to have the power of

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

THE FORMATION OF VEGETABLE MOULD, THROUGH THE ACTION OF WORMS WITH OBSERVATIONS ON THEIR HABITS. By CHARLES DARWIN, LL.D., F.R.S. WITH ILLUSTRATIONS. SEVENTH THOUSAND (CORRECTED). LONDON: JOHN MURRAY, ALBEMARLE STREET. 1882. The right of Translation is reserved. [page ii

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

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

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

fetched; for we thus attribute to the worm attention and some mental power, nevertheless I can see no reason to doubt the justice of the comparison. Although worms cannot be said to possess the power of vision, their sensitiveness to light enables them to distinguish between day and night; and they thus escape extreme danger from the many diurnal animals which prey on them. Their withdrawal into their burrows during the day appears, however, to have become an habitual action; for worms kept in

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

both of which are devoured with much relish by worms. Small square pieces of fresh and half-decayed cabbage-leaves and of onion bulbs were on nine occasions buried in my pots, beneath about of an inch of common garden soil; and they were always discovered by the worms. One bit of cabbage was discovered and removed in the course of two hours; three were removed by the next morning, that is, after a single night; two others after two nights; and the seventh bit after three nights. Two pieces of

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

no sign of a burrow; and twice the buried objects were laid on pieces of tin-foil which were not in the least displaced. It is of course possible that the worms whilst moving about on the surface of the ground, with their tails affixed within their burrows, may have poked their heads into the places where the above objects were buried; but I have never seen worms acting in this manner. Some pieces of cabbage-leaf and of onion were twice buried beneath very fine feruginous sand, which was

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

occasionally and very slightly nibbled. These latter four kinds of leaves do not differ in texture in a manner which could make them disagreeable to worms; they all have a strong taste, but so have the four first mentioned kinds of leaves; and the wide difference in the result must be attributed to a preference by the worms for one taste over another. Mental Qualities. There is little to be said on this head. We have seen that worms are timid. It may be doubted whether they suffer as much pain when

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

secretion of the higher animals, are acted on by that from the pancreas.* The half-decayed or fresh leaves which worms intend to devour, are dragged into the mouths of their burrows to a depth of from one to three inches, and are then moistened with a secreted fluid. It has been assumed that this fluid serves to hasten their decay; but a large number of leaves were twice pulled out of the burrows of worms and kept for many weeks in a very moist atmosphere under a bell-glass in my study; and

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

have been known to contain as much as 72 per cent. of lime. Worms therefore would be liable to become charged with this earth, unless there were some special means for its excretion; and the calciferous glands are well adapted for this purpose. The worms which live in mould close over the chalk, often have their intestines filled with this substance, and their castings are almost white. Here it is evident that the supply of calcareous matter must be superabundant, Nevertheless with several

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

seen on one occasion, when a large worm lying beneath a flaccid cabbage leaf tried to drag it away; for the surface of the leaf directly over the end of the worm's body became deeply pitted. On another occasion a worm suddenly lost its hold on a flat leaf; and the anterior end of the body was momentarily seen to be cup-formed. Worms can attach themselves to an object beneath water in the same manner; and I saw one thus dragging away a submerged slice of an onion-bulb. The edges of fresh or

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

plugging-up process may serve for all the above purposes. Whatever the motive may be, it appears that worms much dislike-leaving the mouths of their burrows open. Nevertheless they will reopen them at night, whether or not they can afterwards close them. Numerous open burrows may be seen on recently-dug ground, for in this case the worms eject their castings in cavities left in the ground, or in the old burrows, instead of piling them over the mouths of their burrows, and they cannot collect

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

drawn in by the tips of the needles. These worms, however, worked in a careless or slovenly manner; for the leaves were often drawn in to only a small depth; sometimes they were merely heaped over the mouths of the burrows, and sometimes none were drawn in. I believe that this carelessness may be accounted for either by the warmth of the air, or by its dampness, as the pots were covered by glass plates; the worms consequently did not care about plugging up their holes effectually. Pots tenanted

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

5 had been previously drawn in by the base, for this part had been gnawed. Again, I collected a handful of petioles lying loose on the ground close to some plugged-up burrows, where the surface was thickly strewed with other petioles which apparently had never been touched by worms; and 14 out of 47 (i.e. nearly one-third), after having had their bases gnawed had been pushed out of the burrows and were now lying on the ground. From these several facts we may conclude that worms draw in some

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

petioles of the Clematis could certainly have been drawn in with equal ease by the base and apex; yet three times and in certain cases five times as many were drawn in by the apex as by the base. It might have been thought that the foot-stalks of leaves would have tempted the worms as a convenient handle; yet they are not largely used, except when the base of the blade is narrower than the apex. A large number of the petioles of the ash are drawn in by the base; but this part serves the worms as

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

choice does not appear to be determined by the divergence of the two needles, and the consequent advantage or necessity of drawing them into their burrows by the base. With respect to the triangles of paper, those which had been drawn in by the apex rarely had their bases creased or dirty; and this shows that the worms had not often first tried to drag them in by this end. If worms are able to judge, either before drawing or after having drawn an object close to the mouths of their burrows

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

between the sides of the pot and the earth, which had been moderately pressed down. On a third occasion three large worms and a small one were placed on loose mould well mixed with fine sand and firmly pressed down, and they all disappeared, except the tail of one, in 35 minutes. On a fourth occasion six large worms were placed on argillaceous mud mixed with sand firmly pressed down, and they disappeared, except the extreme tips of the tails of two of them, in 40 minutes. In none of these cases, did

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

seen; but not a single leaf was drawn into these burrows. These castings from their blackness and from the nature of the subsoil could not have been brought up from a greater depth than 6 or 8 inches. On what could these worms have subsisted during this whole time, if not on matter contained in the black earth? On the other hand, whenever a large number of leaves are drawn into the burrows, the worms, seem to subsist chiefly on them, for few earth-castings are then ejected on the surface. This

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

prevented the retreat of the worms into their burrows; and these structures would have resembled traps armed with converging points of wire, rendering the ingress of an animal easy and its egress difficult or impossible. The skill shown by these worms is noteworthy and is the more remarkable, as the Scotch pine is not a native of this district. After having examined these burrows made by worms in confinement, I looked at those in a flower-bed near some Scotch pines. These had all been plugged up in

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

abound in Iceland, and are known to exist in the West Indies, St. Helena, Madagascar, New Caledonia and Tahiti. In the Antarctic regions, worms from Kerguelen Land have been described by Ray Lankester; and I found them in the Falkland Islands. How they reach such isolated islands is at present quite unknown. They are easily killed by salt-water, and it does not appear probable that young worms or their egg-capsules could be carried in earth adhering to the feet or beaks of land-birds. Moreover

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

CHAPTER III. THE AMOUNT OF FINE EARTH BROUGHT UP BY WORMS TO THE SURFACE. Rate at which various objects strewed on the surface of grassfields are covered up by the castings of worms The burial of a paved path The slow subsidence of great stones left on the surface The number of worms which live within a given space The weight of earth ejected from a burrow, and from all the burrows within a given space The thickness of the layer of mould which the castings on a given space would form within a

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

about 2 inches into the ground; more especially if we bear in mind that a good deal of the finest earth would have been washed by heavy rain from the castings ejected on the sloping border down to the level of the field. Some fresh castings were seen close to the stone. Nevertheless, on digging a large hole to a depth of 18 inches where the stone had lain, only two worms and a few burrows were seen, although the soil was damp and seemed favourable for worms. There were some large colonies of ants

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

lower level some of the finest earth which is continually being brought to the surface by worms. How great a thickness vegetable mould ever attains, I have not had good opportunities for observing; but in the next chapter, when we consider the burial of ancient buildings, some facts will be given on this head. In the two last chapters we shall see that the soil is actually increased, though only to a small degree, through the agency of worms; but their chief work is to sift the finer from the

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

cleared. On the previous night there had been some heavy rain, which washed the surface clean, and now the mouths of forty burrows were counted. Parts of the concrete were seen to be solid, and had never been penetrated by worms, and here the rain-water lodged. Sept. 5th. Tracks of worms, made during the previous night, could be seen on the surface of the floor, and five or six vermiform castings had been thrown up. These were defaced. Sept. 12th. During the last six days, the worms have not been

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

up by the worms with their castings, as soon as they were able to penetrate the wall. Rain-water, oozing down the burrows would also carry fine dark-coloured particles into every crevice. Mr. Joyce was at first very sceptical about the amount of work which I attributed to worms; but he ends his notes with reference to the last-mentioned wall by saying, This case caused me more surprise and brought more conviction to me than any other. I should have said, and did say, that it was quite

33%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

neutralise the acids thus generated; for the digestive fluid of worms will not act unless it be alkaline. As the contents of the upper part of their intestines are acid, the acidity can hardly be due to the presence of uric acid. We may therefore conclude that the acids in the alimentary canal of worms are formed during the digestive process; and that probably they are nearly of the same nature as those in ordinary mould or humus. The latter are well known to have the power of de-oxidising or

33%

A2569 Review: Anon. 1882. [Review of Earthworms]. Harper's New Monthly Magazine, 65 (June): 153-154. Text PDF

other creatures. But its more immediate subject is the amount of earth which is brought up by worms from beneath the surface in the form of castings, and is afterward spread out more or less completely by the rain and wind, and the part which worms have thereby played in the burial of ancient buildings and remains, and in the pulverization and denudation of the land. Among the interesting conclusions reached by Mr. Darwin, bearing upon the important part that worms have played in the history of the

32%

A1165 Review: Anon. 1882. [Review of] The formation of vegetable mould through the action of worms. The Daily Record-Union (Sacramento) (1 July): 4. Text PDF

. This would give a weight of 356 pounds in worms. Mr. Darwin estimates that the worms on one of his fields must have passed the earth through their bodies, in the course of a year, at the rate of over eighteen toes per acre. It will be perceived from these figures that the earthworms may easily play a very important part in producing changes of the earth's surface, and that in hilly regions the operation of the worms must hasten the denudation of the soil very greatly. The influence of earth worms

32%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

in this case it is improbable that the worms could ever have obtained leaves. Mr. A. C. Horner confirms this account, as he has seen castings in the cellars of his house, which is an old one, at Tonbridge. But the best evidence, known to me, of worms subsisting for at least considerable periods of time solely on the organic matter contained in earth, is afforded by some facts communicated to me by Dr. King. Near Nice large castings abound in extraordinary numbers, so that 5 or 6 were often

31%

A1164 Review: Anon. 1882. [Review of] The formation of vegetable mould, through the action of worms. The Daily Chronicle (Knoxville) (17 February): 1. Text PDF

not merely worms that he studies but the waste from their bodies, and it is subject for no little wonder when one sees through his eyes. It is estimated that there are about 53,767 worms to an average acre of land. These creatures, whether they eat or swallow dirt for the purpose of making their way through the ground, are all the time throwing out of their bodies the waste material just at the surface of the earth, and this is sufficient to cover the ground and gradually to bury the natural

29%

A1326 Review: Anon. 1882. [Review of Earthworms] Professor Darwin and the worms. Ballarat Courier (Victoria), (1 April): 1. Text PDF

The Complete Work of Charles Darwin Online [page] 1 Professor Darwin and the worms. Darwin, in his latest work, estimates that there are in gardens 53,767 worms to the acre, and that they would weigh 356 ib. Having four or five gizzards a piece, each worm is able to digest a large amount of coarse food, and to bring 16 tons per acre to the surface per annum. Mr Darwin says that a field near his home has been cleared of cobble stones within his remembrance, and this not so much from the fact

29%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

THE FORMATION OF VEGETABLE MOULD, THROUGH THE ACTION OF WORMS, WITH OBSERVATIONS ON THEIR HABITS. INTRODUCTION. The share which worms have taken in the formation of the layer of vegetable mould, which covers the whole surface of the land in every moderately humid country, is the subject of the present volume. This mould is generally of a blackish colour and a few inches in thickness. In different districts it differs but little in appearance, although it may rest on various subsoils. The

29%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

Fig.1. Diagram of the alimentary canal of an earthworm (Lumbricus), copied from Ray Lankester in 'Quart. Journ. of Microscop. Sc.' vol. xv. N.S. pl. vii. latter organ is lined with a smooth thick chitinous membrane, and is surrounded by weak longitudinal, but powerful transverse muscles. Perrier saw these muscles in energetic action; and, as he remarks, the trituration of the food must be chiefly effected by this organ, for worms possess no jaws or teeth of any kind. Grains of sand and small

29%

F1362 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. 6th thousand (corrected). London: John Murray. Text Image PDF

CHAP. III. BROUGHT UP BY WORMS. 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

29%

F1364 Book: Darwin, C. R. 1882. The formation of vegetable mould, through the action of worms, with observations on their habits. Seventh thousand. Corrected by Francis Darwin. London: John Murray. Text Image PDF

already alluded to, which appeared in 1877.* Before entering on details with respect to the castings, it will be advisable to give some account of the habits of worms from my own observations and from those of other naturalists. * My father's attention was called by Professor Hensen to P. E. M ller's work on Earthworms in 'Tidsskrift for Skovbourg,' Band iii. Heft 1 and 2, Copenhagen, 1878. He had, however, no opportunity of consulting M ller's work. F. D. [page]

29%

F1985 Periodical contribution: Darwin, C. R. 1881. [Letter to W. Bailey 3584, 28 Dec 1881, Down Statement about a beetle-hunting worm is new to Charles Darwin. ALS 1p] Herald 1882 [Provenance: BL (Add 50957:22)] Text

Darwin, C. R. 1882. [Letter to W. Bailey about a beetle-hunting worm] Herald [Provenance: BL (Add 50957:22)] [page?] Down Beckenham Kent December 28th 1881 Dear Sir I am much obliged for your letter. The statement about the beetle, probably a Staphylinus, hunting a worm by scent is quite new to me.— I have received another account of the noise made by worms, whilst dragging leaves into their burrows— Dear Sir Yours faithfully obliged Ch. Darwin The British Library (Add 50957:22

28%

A2253 Review: Anon. 1882. [Review of] Earthworms. Friends' Review: A Religious, Literary and Miscellaneous Journal (Philadelphia), 35 (28 January): 399. Text

The Complete Work of Charles Darwin Online [page] 399 Earthworms. -In his last printed work, Darwin estimates that there are in gardens 53,767 worms to the acre, and that they would weigh 356 pounds. Having four or five gizzards apiece, each worm is able to digest a large amount of coarse food, and to eat his peck of dirt in a brief space of time. Careful weighing of the castings brought to the surface by worms shows that they sometimes amount to sixteen tons per acre annually -sufficient to