May 15, 1884] 



NATURE 



57 



begin, and I have often been told that it does so early on the first 

 Sunday of March, G.M.T. 



What I said about the magpie beginning on the first Sunday 

 (old style) was founded partly on report, but mainly on personal 

 observation extending over some years at one breeding-place, 

 where I have often seen them at work for the first time on this 

 particular morning, and on one occasion in another locality on 

 the same day. 



This instinct is not confined to any particular tribe or order, but 

 is common, I think, to all wild fowl, and the two instances given 

 by Dr. Rae (vol. xxx. p. 7) of the regularity with which certain 

 birds pass north to their breeding-grounds is precisely the point 

 at issue, as I believe they begin work as soon as they arrive. 



Scientific accuracy has not yet been directed to the subject, 

 but there can be no doubt that from some cause, possibly a 

 sharper and better defined division of summer and winter in 

 former ages, all the feathered tribe have inherited an instinct in 

 nest-building and in the time of their arrival at and departure 

 from their breeding-grounds which guides them to a day in 

 many cases without reference to the state of the weather. 



Wm. Brown 



112, West Regent Street, Glasgow, May 5 



Watts's "Inorganic Chemistry" 

 The review of my "Inorganic Chemistry" in Nature 

 of May 1 (p. 3) appears to have been written without much 

 knowledge of the previous history of the work. The reviewer, 

 indeed, writes as if he were criticising an entirely new book, 

 whereas a glance at the preface might have shown him that the 

 volume in question is the first part of the thirteenth edition of 

 Fownes's well-known "Manual of Chemistry," the first edition 

 of which was published in 1844. H. Watts 



j 5 1, King Henry's Road, N.W. 



The Recent Earthquake 



I notice that Mr. Topley, at the conclusion of his communi- 

 cation to you respecting the recent earthquake in Essex, remarks, 

 "but at present we know of no observations in the central 

 parts of Kent, Surrey, or Sussex." I wish therefore to mention, 

 that although I did not myself notice anything in connection 

 therewith, yet an invalid neighbour of mine, lying in bed, dis- 

 tinctly heard a rumbling noise about 9I1. 20m., and a moment 

 afterwards perceived some pot plants in front of his window sway 

 to and fro. This is the only incident with which I have been 

 made acquainted. C. L. Prince 



The Observatory, Crowborough, Sussex, May 3 



The rise in the Essex waters detailed in my letter of last week 

 still continues. Mr. Radforde Sharpe has kindly sent me the 

 following additional heights that the water rises from Messrs. 

 Courtauld and Co.'s well, at Bocking, Braintree, in inches above 

 the surface of the ground : — 



May 6 40J inches I May 9 39^ inches 



>, 7 34 ,, ,, 10 39! „ 



,, S 40 ,, j ,,12 44 ,, 



At Colchester Corporation Waterworks Mr. C. Clegg, C.E., 

 reports the rise recorded is still maintained. 



Museum, Jermyn Street, S.W. C. E. De Rance 



W. H. France. — Any good entomological text-book will give 

 you the information you ask for. 



NOTES ON EARTHWORMS 

 "PVER since our great naturalist called attention to the 

 ■'-* common earthworm, we watch them with entirely 

 different eyes as they creep timidly out on to the lawn or 

 hurry across the gravel walk ; as they collect the dead 

 leaves or bits of string and cloth we may have dropped 

 the evening before, or heap up their household refuse 

 outside the entrance to their home. 



He long ago pointed out its importance as a geological 

 agent. The surface of the ground would be very different 

 were it not that the earthworm is for ever at work bringing 

 in the decaying vegetation and converting it into mould. 



And, more than this, the superficial deposits are often 

 modified to a considerable depth by the earthworms, 

 which, carrying the earth mouthful by mouthful, and the 

 gravel stone by stone, invert the order of stratification. 



But we must not push this explanation of the origin of 

 the universal surface mould too far. I received one 

 caution from Darwin himself, many years ago when 

 I was talking to him about the manner in which the 

 chalk with which the land was dressed in Kent worked 

 down. He told me to be careful to bear in mind the 

 action of the great Kentish plough as it year by year 

 turned swathe after swathe down the slopes. The result 

 of this plough-down is clearly distinguishable from worm- 

 mould. In his work on earthworms also he refers to 

 another mould- forming agent of more universal operation 

 and hardly less important cumulative effect. My atten- 

 tion was first directed to it by a lecture I heard delivered 

 by Stoppani in Milan many years ago, in which he was 

 explaining the action of the wind in modifying the surface 

 of the earth, and especially in carrying dust, organic and 

 inorganic. Ricbthofen and Drew have thus explained 

 the origin of the loam that covers half Asia; and Mr. 

 Clement Reid has recently extended the same kind of 

 observation to Great Britain {Geol. Ma°., April 1S84). 

 Without this addition we can hardly explain how earth- 

 worms could find the material for the manufacture of the 

 mould which often fills the interstices of the ruins of a 

 buried city. 



We find, commonly, isolated tumps of moss-covered 

 soil, and every gradation from that up to the large patches 

 of mould which hang like little gardens on each sheltered 

 ledge, where the greater p3rt of the material must evi- 

 dently have been carried from elsewhere and not have 

 been brought up from below ; where it is obvious, from 

 the character of the rocks, that the principal part of the 

 mould cannot have been derived so much from them as 

 from the wind-carried fragments of organic and inorganic 

 material and the decomposition of the vegetation that 

 soon began to grow upon it. 



But we find also that the earthworms soon appear in 

 such places, and set to work to mix up and modify all this 

 various stuff that has by various agencies been brought 

 together. 



As squirrels, burying acorns and nuts in the autumn, have 

 planted many an oak forest and hazel grove, so it is pro- 

 bable that the earthworms plant many of the ash and 

 sycamore trees that we see perched in out-of-the-way 

 corners, where it is difficult to explain how the blown 

 seed can have got covered by mould enough to allow it 

 to germinate. If an overhanging tree drops the seed, or 

 the wind carries it anywhere near the worm's feeding- 

 ground, it is dragged in and planted in leaf mould, and 

 kept moist till spring time. At this time of the year 

 we see clusters of sycamore seedlings growing up together 

 out of the little worm-hills into which they had been 

 dragged heavy end first. 



It is therefore interesting to inquire into the various 

 reasons that should make earthworms travel and occupy 

 new ground. Round the margin of an overcrowded 

 colony we should expect them to spread. They cannot 

 live under water, so they have to move away before a 

 flood. It has been stated that " they may live when 

 completely submerged in water for nearly four months " 

 (Romanes reviewing Darwin, NATURE, vol. xxiv. p. 553). 

 But they were killed off by a flood of a couple of days' 

 duration in the Backs of the Colleges at Cambridge in 

 August 1S79. Some of them seem to have got on to the 

 paths, which are raised above the surrounding meadows, 

 and there died. Where the greatest number were found 

 dead the ground had been submerged for a longer time. 

 The following carefully recorded observations by the Rev. 

 Henry Russell, of St. John's College, are worth noting : — 



" On Sunday, August 3, 1879, our paddock (the inclosed 

 space in which the men play at lawn tennis, in front of the 



