14 



KNOWLEDGE 



[Nov. 4, 1881. 



DARWIN- ON MOULD AND WORMS.* 



No man of si-ionco of our clay uiKK'r.stancts l)ettt'r, or 

 applies iiioro tliorouglily, than Darwin, the principle 

 laid clown by Lord Bacon, that " Man, as the minister and 

 intorprotcr of nature, does and understands as much as his 

 observations on the order of nature permit hiui, and neither 

 knows nor is capable of more. " To one who rightly 

 apprehends this, the fundamental principle of modem 

 scientific research, small things and great, so only that they 

 illustrate the order of nature, are alike worthy of study. 

 He may carry iiis survey over the depths of space, or into 

 the^structure of a microscopic creature ; he may e.xtond liis 

 view into the remote past and the distant future, or he 

 may limit the range of his vision to phenomena taking 

 place in a second or in a yet shorter time : but only in so 

 far as liis pui-pose is to determine tlic order of nature's 

 works, is he the true minister and interpreter of nature. 

 The modern student of science, following this principle, is 

 in strong contrast with the pliilosophers of the Greek 

 school, who, little disposed to pursue observations, evinced, 

 as Humboldt has said, " inexhaustible fertility in giving 

 the most varied interpretation of half-perceived facts;" and, 

 as Bacon himself said, " Laid theii- whole stress upon 

 intense meditation, and a continual exercise and perpetual 

 agitation of the mind ;" and so were led to frame systems 

 on insufficent knowledge, and to explain false systems by 

 false hypotheses. Doubtless, a philosopher of that school 

 would have looked with contempt on a Darwin studying the 

 movements of plants, the ways of bees, the breeds of pigeons, 

 and analysing the plaj- of features in joy or in sorrow, 

 in anger or in pleasure. It would have seemed to him far 

 worthier to educe from his moral consciousness ideas as to 

 the true position of worms in the scale of being, than to 

 devote years to the actual study of their ways and works. 

 But by the humbler and more lal)orious method the student 

 of science in our day manages to attain, or at least 

 approach, the truth ; the more brilliant philosopher of the 

 olden school educed from his active mind multitudinous 

 errors. 



Darwin's latest treatise, on Vegetable Mould and 

 Earthworms, alFords perhaps the best illustration of his 

 method of all the works that he has yet published. His 

 "Origin of Species" and "Descent of Man" mark an 

 epoch in science ; but such a work as the present illustrates 

 the way by which the new paths have been entered. It is 

 true no one can road those epoch-making works without 

 recognising in every page the kind of work on which their 

 author's mind has been engaged while establishing his 

 theories, or the tone of modern scientific thought. But 

 results have there to be touched on which, in a work like 

 his " Monograph on the Cirripedia," " The Movements and 

 Habits of Climbing Plants," and, above all, the present 

 treatise, are e.xhibited in detail. 



Forty- four years ago Darwiu announced the first results 

 of his study of the formation of vegetable mould, in a 

 paper read before the Geological Society of London. In 

 the interval which has elapsed since then he h.as been 

 accumulating tlie stores of knowledge al>out mould and 

 mould-makers which are presented in the work now before 

 us. 



Perhaps the most remarkable results of Darsvin's observa- 

 tions is the " stupendous work " accomplished by creatures 

 so small and weak. It was objected against the views which 

 he published in 1837, that worms could not possibly bury to 



• " Tho Formation of Vegetable Mould through the Action of 

 Worms, with Observations on their Habits." By CnABLEs Dabwin 

 LL.D., F.R.S. (London : John Murray, 1881.) 



a depth of several inches fragments of cinders, burnt marl, 

 itc, which had been strewn over the surface of mcaidow 

 land. But now Darwin is able to speak confidently of their 

 liurial of the remains of Roman villas and pavements. He 

 shows also how ancient encampments and tumuli have been 

 gradually lowered bj' the agency of wonn.s. Grass-covered 

 slopes undergoporpetual denudation through theirjoperations, 

 th(' covering of grass remaimng 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 science, as formerly in 

 the case of geologj', and more recently in that of the 

 principle of evolution." When men like Sir John 

 Herschel or Sir Charles Lyell have spoken of the efTects of 

 slowly-acting causes in modifying continents and seas, 

 they have been ridiculed by the thoughtless, who cannot 

 see how the downfall of rain, the slow movement of rivers, 

 the play of waves on shore-lines, can produce such results. 

 In like manner the biologist is ridiculed who, noting small 

 changes in various races in short periods (or even in periods 

 which to our conceptions seem long), points to the effect of 

 such changes when multiplied during the lapse of tliose 

 long periods of time of which the earth's crust tells us. 

 But our author has shown how even creatures so tiny and 

 weak as the coral animal have made large islands and 

 long lines of sea-resisting reef, by constant labour^'; and 

 now he shows how under our very feet the despised cairth- 

 worm is changing the form and nature of the land we live 

 on. When wc learn that the rich dark mould in which 

 vegetation thrives best, is matle by wonns, we see that not 

 only the aspect of a country, but the condition of its 

 inhabitants, and even its history, have been modified by 

 their work. So that we may accept in its widest signifi- 

 cance his remark that "it may be doubted whether there 

 are many other animals which have played so important a 

 part in the history of the world as have these lowly 

 creatures." 



The study of the habits of worms in this work is full of 

 interest As in nearly all the author's books, the language 

 is clear and simple. It may be said indeed of this treatise, 

 presenting the fruit of observations so long continued on a 

 subject apparently so little promising, that great though its 

 scientific value unquestionably is, it is better fitted than ' 

 nine-tenths of our works of fiction to while away a weary 

 hour. It merits, however, more than mere reading. It is 

 a work not to be tasted merely, but to be cJiewed and 

 digested. 



We shall hereafter return to this work, to consider more 

 at length some of the interesting results of Mr. Darwin's 

 researches. 



AprLU'ATioKs OK ELECTKiriTY. — Tlic public hardly realise, as yet, 

 a tenth part of the uses to which electricity can bo readily and con- 

 veniently adapted ; and exhibitions will furnish tho best possible 

 means of rendering them familiar with these uses, wliich, in many | 

 cases, are of an essentially domestic character. Electric bells, for I 

 example, although almost universal in large hotels, offices, and i 

 public buildings, make way but slowly in private houses, notwith- ' 

 standing their many advantages. Telephones, in like manner, are > 

 far lo-ss numerous than they ought to be ; and many forms of 

 electrical arrangement ciuitc common in tho United States, and ' 

 found to have great value in saving labour, are scarcely at all in 

 use among ourselves. The electric light is not yet employed in 

 many places for which it is eminently suitable; and its cmplny- 

 mont is still impeded by ditEcuItics of detail which a larger demand 

 would set aside. — Timea. 



