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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
on polished slabs of marble, dolomite and phosphate of lime. They will attack even basalt and sandstone.* But we are not here concerned with agencies which are wholly independent of the action of worms. The combination of any acid with a base is much facilitated by agitation, as fresh surfaces are thus continually brought into contact. This will be thoroughly effected with the particles of stone and earth in the intestines of worms, during the digestive process; and it should be remembered
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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
lying the chalk (the residue of its dissolution by rain-water) or form the chalk itself. 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,* as une v ritable armature. The gizzard is surrounded by powerful
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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
tenuissim terr , veluti in pulverem redact . * Perrier also speaks of I' tat de p te excessivement fine laquelle est r duite la terre qu'ils rejettent, c. As the amount of trituration which the particles of earth undergo in the gizzards of worms possesses some interest (as we shall hereafter see), I endeavoured to obtain evidence on this head by carefully examining many of the fragments which had passed through their alimentary canals. With worms living in a state of nature, it is of * Morren, 'De
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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
gizzards of some worms dug out of a thin bed of mould over the chalk, there were many wellrounded small fragments of chalk, and two fragments of the shells of a land-mollusc (as ascertained by their microscopical structure), which latter were not only rounded but somewhat polished. The calcareous concretions formed in the calciferous glands, which are often found in their gizzards, intestines, and occasionally in their castings, when of large size, sometimes appeared to have been rounded; but
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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
rounded; and it is not credible that these could have suffered so much corrosion from the action of carbonic acid in the course of only seven years. Much better evidence of the attrition of hard objects in the gizzards of worms, is afforded by the state of the small fragments of tiles or bricks, and of concrete in the castings thrown up where ancient buildings once stood. As all the mould covering a field passes every few years through the bodies of worms, the same small fragments will
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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
overlying the buried tesselated pavement, through which worm-burrows passed; and these castings contained innumerable particles of tiles and bricks, of concrete and cement, the majority of which had manifestly undergone some or much attrition. There were also many minute flakes of a micaceous slate, the points of which were rounded. If the above supposition, that in all these cases the same minute fragments have passed several times through the gizzards of worms, be rejected, notwithstanding
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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
consider the evidence above given, there can be little doubt that the fragments, which serve as millstones in the gizzards of worms, suffer, when of a not very hard texture, some amount of attrition; and that the smaller particles in the earth, which is habitually swallowed in such astonishingly large quantities by worms, are ground together and are thus levigated. If this be the case, the terra tenuissima, the p te excessivement fine, of which the castings largely consist, is in part due to
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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
even on a level field, to leeward, whilst they are soft; and in like manner the pellets when they are dry. If the wind blows in nearly the direction of an inclined surface, the flowing down of the castings is much aided. The observations on which these several statements are founded must now be given in some detail. Castings when first ejected are viscid and soft; during rain, at which time worms apparently prefer to eject them, they are still softer; so that I have sometimes thought that
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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
will never be removed as long as the wood lasts; and mould will here tend to accumulate to the depth at which worms can work. I tried to procure evidence as to how much mould is blown, whilst in the state of castings, by our wet southern gales to the north-east, over open and flat land, by looking to the level of the surface on opposite sides of old trees and hedge-rows; but I failed owing to the unequal growth of the roots of trees and to most pasture-land having been formerly ploughed. On an
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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
on the crowns; but this would naturally follow from the finer earth having been washed from the crowns into the furrows before the land was well clothed with turf; and it is impossible to tell what part worms may have played in the work. Nevertheless from what we have seen, castings would certainly tend to flow and to be washed during heavy rain from the crowns into the furrows. But as soon as a bed of fine earth had by any means been accumulated in the furrows, it would be more favourable for
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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
and the particles composing it are thus rubbed together. By these means fresh surfaces are continually exposed to the action of the carbonic acid in the soil, and of the humus-acids which appear to be still more efficient in the decomposition of rocks. The generation of the humus-acids is probably hastened during the digestion of the many half-decayed leaves which worms consume. Thus the particles of earth, forming the superficial mould, are subjected to conditions eminently favourable for
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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
delivered into the sea by the Mississippi, that its enormous drainage-area must on an average be lowered 00263 of an inch each year; and this would suffice in four and half million years to lower the whole drainage-area to the level of the sea-shore. So that, if a small fraction of the layer of fine earth, 2 of an inch in thickness, which is annually brought to the surface by worms, is carried away, a great result cannot fail to be produced within a period which no geologist considers extremely
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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
all buried beneath the accumulated castings of worms, and are thus brought in a more or less decayed state within reach of the roots of plants. Worms likewise drag an infinite number of dead leaves and other parts of plants into their burrows, partly for the sake of plugging them up and partly as food. The leaves which are dragged into the burrows as food, after being torn into the finest shreds, partially digested, and saturated with the intestinal and urinary secretions, are commingled with
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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
Hensen* placed two worms in a vessel 18 inches in diameter, which was filled with sand, on which fallen leaves were strewed; and these were soon dragged into their burrows to a depth of 3 inches. After about 6 weeks an almost uniform layer of sand, a centimeter ( 4 inch) in thickness, was converted into humus by having passed through the alimentary canals of these two worms. It is believed by some persons that worm-burrows, which often penetrate the ground almost perpendicularly to a depth of
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A2418    Review:     Anon. 1882. [Review of Earthworms]. Sheffield Independent (28 January): 12.   Text
The Complete Work of Charles Darwin Online [page] 12 The worm under our feet is almost always despised, and often treated as an enemy, and the early birds that are supposed to breakfast upon it are welcomed as if, by devouring it, they did some great good to the farmer and the gardener. Many persons will no doubt be surprised to learn that the insignificant worms is one of our best friends. Mr. Darwin, in his lately published book entitled The Action of Worms in the Formation of Vegetable
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A2951    Book:     Bacon, G. W. [1882]. The life of Charles Darwin, with British opinion on evolution. Compiled by G. W. Bacon, F.R.G.S. London: G. W. Bacon & Co.   Text   Image   PDF
Vegetable Mould through the Action of Worms. That work treats of the share worms have had in the formation of the layer of vegetable mould which cover the whole surface of the land in every moderately humid country. Darwin's observations led him to conclude that the vegetable mould over the whole country has passed many times through the intestinal canals of those creatures. It might be supposed that little really interesting could be said of the worm; but Mr. Darwin has invested this humble theme
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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
CONTENTS. Introduction……Pages 1-7 CHAPTER I. HABITS OF WORMS. Nature of the sites inhabited—Can live long under water—Nocturnal—Wander about at night —Often lie close to the mouths of their burrows, and are thus destroyed in large numbers by birds—Structure —Do not possess eyes, but can distinguish between light and darkness—Retreat rapidly when brightly illuminated, not by a reflex action—Power of attention—Sensitive to heat and cold—Completely deaf—Sensitive to vibrations and to touch—Feeble
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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
CONTENTS. Introduction page 1 7 CHAPTER I. HABITS OF WORMS. Nature of the sites inhabited Can live long under water Nocturnal Wander about at night often lie close to the mouths of their burrows, and are thus destroyed in large numbers by birds Structure Do not possess eyes, but can distinguish between light and darkness Retreat rapidly when brightly illuminated, not by a reflex action Power of attention Sensitive to heat and cold Completely deaf Sensitive to vibrations and to touch Feeble
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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 WARMS, 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 apperance, although it may rest on various subsoils. The
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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
beneath the general level of the ground, and of 8 inches beneath the top of the sloping turf-covered border. Sufficient evidence has now been given showing that small objects left on the surface of the land where worms abound soon get buried, and that large stones sink slowly downwards through the same means. Every [page] 16
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F1416    Book contribution:     Darwin, C. R. 1882. [Extracts from Darwin's draft chapter 10 of Natural selection]. In Romanes, G. J., Animal intelligence. London: Kegan Paul Trench & Co.   Text   Image   PDF
Wolf, 426-36; avoiding gun-traps, 431; drawing up fish-lines to take fish, 431; collective instinct in hunting, 433, 436 Wolverine, 347-50 Wood, Rev. G. J., on spiders weighting their webs, 221 Woodcock, conveying young on back, 289 Woodpecker, ant-eating, its instinct of storing food, 285; nidification, 293 Words, understanding of, by bees, 189; by talking birds, 267-9 Worms, apparent intelligence of, 24 Wright, his portrait-painting recognised by a dog, 454-5 YARRELL, on fish, 246; on in
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A1324    Review:     Anon. 1882. [Review of Earthworms] What man owes to Earth-worms. Sunday Morning Call (12 February): 6.   Text   PDF
earth, it seems, would practically be a desert were it not for the worm. The vegetable mold which makes the soil fruitful is due to its labors, and the secret of its value is that it eats dirt, which has been so well characterized as matter in the wrong place. In one acre there is an average of 53,767 worms. The prodigious result of their is shown by an investigation of a field in Kent, England, where Dr. Darwin found that the worms had thrown up digested soil amounting to eighteen tons per acre in
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A1162    Review:     Anon. 1882. [Review of] The formation of vegetable mould through the action of worms, with observations on their habits. Sydney Morning Herald (1 May): 7.   Text   PDF
diet, for in extremity they will eat anything, even one another. The amount of earth brought up to the surface by worms is a matter of long observation and nice calculation. In a field belonging to Mr. Wedgwood, of Maer Hall, Staffordshire, mould to an average thickness of .22 of an inch had been annually brought up by the worms, and had been spread over the surface of this field. At the same rate, the whole surface of the globe would be covered with a mould 22 inches deep in the course of a
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A1163    Review:     [Macleay, W. J.] 1882. [Review of] The formation of vegetable mould, through the action of worms. The Proceedings of the Linnean Society of New South Wales, VI: 864-5.   Text   PDF
the covering of grass remaining all the time intact, and even the inclination of the slope remaining unchanged. It may well seem incredible to the superficial reasoner that creatures like worms - small, weak, and soft-bodied - should produce such results; nay, results far greater in the course of time, changing as they do the entire aspect of a country. It is this inability, as Darwin well remarks, to sum up the effects of a continually recurring cause which has often retarded the progress of
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A2264    Review:     Anon. 1882. [Review of Earthworms]. Vegetable Mould and Earth Worms. Yale Literary Magazine, 47 (January): 170-171.   Text
The Complete Work of Charles Darwin Online [page] 170 Vegetable Mould and Earth Worms. By Charles Darwin, LL.D., F.R.S. Illustrated. New York: D. Appleton Co. For sale by Judd. Despite the unattractive subjects treated of in this book, we venture to say that it is as valuable and interesting a work as has appeared for some time. It is a book which few but Mr. Darwin could have produced, and still fewer could be found, we think, possessing the patience in investigation which its production
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A2850    Periodical contribution:     Anon. 1882. [Obituary of] Darwin. Medical Register 1 (15 May): 36-7.   Text
. Movements and Habits of Climbing Plants. Insectivorous Plants. The Effects of Cross and Self Fertilization in the Vegetable Kingdom. Different Forms of Flowers of the same Species. The Power of Movement in Plants. The Formation of Vegetable Mould through the Action of Worms. [page] 3
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A2851    Periodical contribution:     Anon. 1882. Obituary. Charles Robert Darwin. The Medical Tribune 4: 222-3.   Text
the world his treatise on the Descent of Man and Selection in Relation to Sex. He has since published many separate papers, notably on The Geology of the Falkland Islands; The Formation of Vegetable Mould Through the Action of Worms; On the Expression of the Emotions in Men and Animals, and on Volcanic Phenomena, and The Distribution of Erratic Boulders, both the latter relating to South America. He received the Copley and the Royal medals from the Royal Society, and the Wollaston Palladian
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A2852    Periodical contribution:     Anon. 1882. [Obituary of] Charles Darwin. Michigan Medical News 5, no. 8 (10 May): 132-3.   Text
Formation of Vegetable Mould through the Action of Worms in 1881. This enormous volume of work has been accomplished by untiring industry, in spite of frequent illnesses which to most men would have been accounted sufficient cause for idleness. Personally, Mr. Darwin was greatly loved by his social and scientific acquaintances, and his home life was the happiest. He leaves five sons and two daughters, all of superior ability and high character. Mr. Darwin died at his residence near Orpington
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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
study during many months worms in pots filled with earth, * 'Leçons de Geologie Pratique,' tom. i. 1845, p. 140. [page]
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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
INTRODUCTION. about twice as many worms in gardens as in corn-fields.* With respect to prairies élevées, I do not know how it may be in France, but nowhere in England have I seen the ground so thickly covered with castings as on commons, at a height of several hundred feet above the sea. In woods again, if the loose leaves in autumn are removed, the whole surface will be found strewed with castings. Dr. King, the superintendent of the Botanic Garden in Calcutta, to whose kindness I am indebted
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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. I. THEIR STRUCTURE. consists of from 100 to 200 almost cylindrical rings or segments, each furnished with minute bristles. The muscular system is well developed. Worms can crawl backwards as well as forwards, and by the aid of their affixed tails can retreat with extraordinary rapidity into their burrows. The mouth is situated at the anterior end of the body, and is provided with a little projection (lobe or lip, as it has been variously called) which is used for prehension. Internally
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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. I. THEIR SENSES. different occasions might be explained, either by the degree of extension of their skin and its consequent transparency, or by some particular incidence of the light; but I could discover no such relation. One thing was manifest, namely, that when worms were employed in dragging leaves into their burrows or in eating them, and even during the short intervals whilst they rested from their work, they either did not perceive the light or were regardless of it; and this
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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. I. or consciousness of the animal, as if it were an automaton. But the different effect which a light produced on different occasions, and especially the fact that a worm when in any way employed and in the intervals of such employment, whatever set of muscles and ganglia may then have been brought into play, is often regardless of light, are opposed to the view of the sudden withdrawal being a simple reflex action. With the higher animals, when close attention to some
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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. I. THEIR SENSES. 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 they preferred the green, the red being either wholly neglected or much less gnawed. On two other occasions, however, they seemed to prefer the red. Half-decayed leaves of the red variety and fresh
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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. I. and others at first treated them with ether. This produces no effect; but they are quickly dissolved with effervescence in acetic acid, and when oxalate of ammonia is added to the solution a white precipitate is thrown down. \Ve may therefore conclude that they contain carbonate of lime. If the cells are immersed in a very little acid, they become more transparent, look like ghosts, and are soon lost to view; but if much acid is added, they disappear instantly. After
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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
structure. How they escape from the gland is a marvel; but that they do escape is certain, for they are often found in the gizzard, intestines, and in the castings of worms, both with those kept in confinement and those in a state of nature. Claparède says very little about the structure of the two anterior glands, and he supposes that the calcareous matter of which the concretions are formed is derived from the four posterior glands. But if an anterior gland which contains only small concretions
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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. I. lamellæ like those in the posterior glands and coated with cellular matter could be plainly seen, together with a multitude of· free calciferous cells readily soluble in acetic acid. When a gland is completely filled with a single large concretion, there are no free cells, as these have been all consumed in forming the concretion. But if such a concretion, or one of only moderately large size, is dissolved in acid, much membranous matter is left, which appears to
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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
fermentations going on in the contents themselves.... In Carnivora the contents of the coecum are said to be alkaline, and naturally the amount of fermentation will depend largely on the nature of the food. * With worms not only the contents of the intestines, but their ejected matter or the castings, are generally acid. Thirty castings from different places were tested, and with three or four exceptions were found to be acid; and the exceptions may have been due * M. Foster, 'A Text-Book of Physiology
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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. I. CALCIFEROUS GLANDS. -tion. * Therefore it seems highly probable that the innumerable calciferous cells, which are poured from the four posterior glands into the alimentary canal of worms, serve to neutralise more or less completely the acids there generated by the half-decayed leaves. We have seen that these cells are instantly dissolved by a small quantity of acetic acid, and as they do not always suffice to neutralise the contents of even the upper part of the alimentary canal, the
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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. ciently tender. They generally seized the thin edge of a leaf with their mouths, between the projecting upper and lower lip; the thick and strong pharynx being at the same time, as Perrier remarks, pushed forward within their bodies, so as to afford a point of resistance for the upper lip. In the case of broad flat objects they acted in a wholly different manner. The pointed anterior extremity of the body, after being brought into contact with an object of this kind
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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. PROTECTION OF THEIR BURROWS. mouth of another. Some of these objects, such as the petioles just named, feathers, c, are never gnawed by worms. In a gravel-walk in my garden I found many hundred leaves of a pine-tree (P. austriaca or nigricans) drawn by their bases into burrows. The surfaces by which these leaves are articulated to the branches are shaped in as peculiar a manner as is the joint between the leg-bones of a quadruped; and if these surfaces had been in the least gnawed
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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. in this manner and to try different methods makes a near approach to intelligence. In the first place 227 withered leaves of various kinds, mostly of English plants, were pulled out of worm-burrows in several places. Of these, 181 had been drawn into the burrows by or near their tips, so that the foot-stalk projected nearly upright from the mouth of the burrow 20 had been drawn in by their bases, and in this case the tips projected from the burrows; and 26 had been
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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. for it is clear that they would not have failed in drawing them in by the base or middle. The leaves of a foreign plant were next searched for, the blades of which were not more pointed towards the apex than towards the base. This proved to be the case with those of a laburnum (a hybrid between Cytisus alpinus and laburnum) for on doubling the terminal over the basal half, they generally fitted exactly; and when there was any difference, the basal half was a little
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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. Petioles. —We will now turn to the petioles or foot-stalks of compound leaves, after the leaflets have fallen off. Those from Clematis montana, which grew over a verandah, were dragged early in January in large numbers into the burrows on an adjoining gravel-walk, lawn, and flower-bed. These petioles vary from 2 1/2 to 4 1/2 inches in length, are rigid and of nearly uniform thickness, except close to the base where they thicken rather abruptly, being here about twice
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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 INTELLIGENCE. necessary in plugging up the burrows, the proportion of those drawn in by the tip (130) to those drawn in by the base (48) was rather less than three to one. That these petioles had been dragged into the burrows for plugging them up, and not for food, was manifest, as neither end, as far as I could see, had been gnawed. As several petioles are used to plug up the same burrow, in one case as many as 10, and in another case as many as 15, the worms may perhaps at
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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. grasshoppers, which are invariably dragged into the burrow by their antennæ. When these were cut off close to the head, the Sphex seized the palpi; but when these were likewise cut off, the attempt to drag its prey into the burrow was given up in despair. The Sphex had not intelligence enough to seize one of the six legs or the ovipositor of the grasshopper, which, as M. Fabre remarks, would have served equally well. So again, if the paralysed prey with an egg
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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
occasion he had drawn a toad out of a hole by its leg. The Sphex failed signally in this respect. Now if worms try to drag objects into their burrows [page] 9
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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. EXCAVATION OF THEIR BURROWS. depth, and was of so poor a nature that weeds could not grow on it. It is therefore highly improbable that it should have been swallowed by the worms as food. Again in a field near my house the castings frequently consist of almost pure chalk, which lies at only a little depth beneath the surface; and here again it is very improbable that the chalk should have been swallowed for the sake of the very little organic matter which could have percolated into
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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. THE COLLAPSE OF OLD BURROWS. the whole ground would be first thickly riddled with holes to a depth of about ten inches, and in fifty years a hollow unsupported space, ten inches in depth, would be left. The holes left by the decay of successively formed roots of trees and plants must likewise collapse in the course of time. The burrows of worms run down perpendicularly or a little obliquely, and where the soil is at all argillaceous, there is no difficulty in believing that the walls
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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. long existed as poor pasture and was so swampy that it trembled slightly when stamped on, was thickly covered with red sand so that the whole surface appeared at first bright red. When holes were dug in this field after an interval of about 2 1/2 years, the sand formed a layer at a depth of 3/4 in. beneath the surface. In 1842 (i.e., 7 years after the sand had been laid on) fresh holes were dug, and now the red sand formed a distinct layer, 2 inches beneath the
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