Nov. I, 1877] 



NATURE 



19 



search the ground round about. They then draw whatever 

 vegetable material they can find into their tubes — fallen stems 

 and leaves and small branches. In the morning one then finds 

 little heaps of plant-fragments projecting at various parts of the 

 surface, and each of them penetrating the tube of a worm. On 

 closer examination it is found that the leaves have each been 

 rolled together by the worm, and then drawn into the tube in 

 such a way that the leaf-stalk projects. The portion of the 

 leaf in the tube is moist and softened, and only in this state are 

 plants consumed by the worm. There are distinct indications 

 that the worm gnaws them, and after some days the meal is 

 ended. The food is never drawn deeper down into the ground. 

 In digging tlie ground at various seasons it was only very rarely 

 that plant remains were found in the subsoil, and probably they 

 got there by accident. 



With reference to the structure of the worm-tubes, some in- 

 teresting facts were established in these researches. In humus 

 their character is difficult to make out, owing to the looseness of 

 the mass. In sand they proceed almost vertically downwards 

 three, four, or even six feet, whereupon they often extend some 

 distance horizontally ; more frequently, however, they terminate 

 without bending. At the end of the tube the worm is found 

 with his head upwards, while round about him the tube is lined 

 with small stones. On the sandy wall of the tube one observes 

 more or less numerous black protuberances which make the sand 

 fertile. These are the secretions of the worm, which, after being 

 removed out of a tenanted tube, are found next morning replaced 

 by fresh matter. They are observed after a few days, when a 

 worm is put in a vessel with clean sand, and allowed to make a 

 tube for itself. Older abandoned tubes are pretty regularly lined 

 with the earth formed by the worm, and some passages are 

 densely filled with black earth. This black substance appears 

 to diffuse somewhat into the sand. 



In about half of the tubes, not quite newly made, M. Hensen 

 found roots of the plants growing at the surface, in the most 

 vigorous development, running to the end of the tube and giving 

 off fine root-hairs to the walls, especially beautiful in the case of 

 leafy vegetables and com. Indeed such tubes must be very 

 favourable to the growth of the roots. Once a root-fibre has 

 reached such a tube it can, following the direction of gravity, 

 grow on in the moist air of the passage, without meeting with 

 the least resistance, and it finds moist, loose, fertile earth in 

 abundance. 



The question whether all roots found in the under-soil have 

 originally grown in the tubes of worms, cannot be answered with 

 certainty. It is certain that the roots of some plants penetrate 

 themselves in the sand, but not to great depths. M. Hensen is 

 of opinion that the tap-roots, and in general such root-forms as 

 grow with a thick point, can force a path for themselves, while 

 the fine and flexible suction-roots have difficulty in obtaining a 

 path into the depths other than what has been previously made 

 for them. Roote of one year's growth especially can penetrate 

 deep into the sub-soil, only where there are earth-worms. 



A microscopical comparison of the earth deposited by the 

 worm shows that it is like the two-year leaf-mould prepared by 

 gardeners for the filling of flower-pots. Most of the plant-cells 

 are destroyed ; still there are present some cells and shreds of 

 tissue, browned and friable, mixed with many sand grains and 

 brown organic fragments. The chemical composition of the 

 worm-earth shows much similarity to that of fertile humus 

 ground. Its fertility, therefore, cannot be doubted, though direct 

 experiments with it are wanting. 



With regard to the numerical value of this action of the 

 earthworm, the following observations by M. Hensen afford 

 some information. 



Two worms were put into a glass pot 1 4 foot in diameter, 

 which was filled with sand to the height of i^ foot, and the 

 surface covered with a layer of fallen leaves. The worms were 

 quickly at work, and afier 14 month many leaves were down 

 3 inches deep into the tubes ; the surface was completely covered 

 with humus i cm. in height, and in the sand were numerous 

 worm-tubes partly fresh, partly with a humus wall 3 mm. thick, 

 partly quite filled with humus. 



Counting, when an opportunity offered, the open worm-tubes 

 in his garden, M. Hensen found at least nine in the square foot. 

 Ino 15 square metres two or three worms were found in the 

 deeper parts each weighing three grammes : thus in the hectare 

 there would be 133,000 worms with 400 kilos, weight. The weight 

 of the secretions of a worm in twenty-four hours was 05 

 grammes. While these numbers are valid only for the locality 



referred to, they yet give an idea of the action of this worm in 

 all places where it occurs. 



The assertion that the earthworms gnaw roots is not proved by 

 any fact ; roots gnawed by worms were never met with, and the 

 contents of the intestine of the worms never included fresh 

 pieces of plants. The experience of gardeners that the earth- 

 worm injures pot plants may be based on the uncovering or 

 mechanical tearing of the roots. 



" Let us take a retrospective glance," concludes the author, 

 "over the action of ths worm in relation to the fertility of the 

 ground. It is clear that no new manure material can be pro- 

 duced by it, but it utilises that which is present in various ways. 

 I. It tends to effect a regular distribution of the natural manure 

 material of fields, inasmuch as it removes leaves and loose plants 

 from the force of the wind and fixes them. 2. It accelerates 

 the transformation of this material. 3. It distributes it through 

 the ground. 4. It opens up the undersoil for the plant roots, 

 5. It makes this fertile. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Oxford. — The University Commissioners are at present occu- 

 pied in taking evidence on the subject of University requirements. 

 The Dean of Christ Church, the Master of Balliol, the Master of 

 University, the Librarian of the Bodleian, Profs. Clifton, 

 Bonamy Price, Bartholomew Price, Stubbs, and others have 

 appeared, or are to appear during the present week, before the 

 Commissioners. 



Mr, Lazarus Fletcher, B.A., of Balliol, has been elected to 

 the vacant Fellowship at University College. Mr. Fletcher 

 obtained a first class in the School of Mathematics in 1875, a 

 first class in that of Natural Science in 1876, and the senior 

 mathematical scholarship in 1876. 



It is proposed to found a high school for the City of Oxford, 

 the mayor, aldermen, and citizens having long felt it a re- 

 proach that, being the site of one of the most ancient and 

 famous of the Universities of Europe, it has been absolutely 

 without any recognised grammar school available for the sons of 

 the citizens. 



London. — Prof. W. K. Clifford, F.R.S., is at present 

 delivering at University College a very interesting course of 

 Lectures on Quaternions. The main object of the course is to 

 bring the physical applications of quaternions as much as possible 

 within the reach of mathematicians of moderate attainments. 



A requisition is in course of signature to the chairman of 

 Convocation of London University, Dr. Storrar, asking that an 

 extraordinary meeting of that body may be convened for the 

 purpose of considering and discussing the following resolution?, 

 and for deciding with reference thereto in such manner as to 

 Convocation may seem fit: — "That it being manifestly inex- 

 pedient that frequent application should be made to the Crown 

 for new and additional charters, it is desirable that provision 

 should be made in any such charter for all changes in the con- 

 stitution of the University, either at the time urgent or likely to 

 be soon required ; and that it being probable that initiative 

 measures will be shortly taken towards procuring such a new or 

 additional charter, the following proposals require the serious 

 consideration of Convocation and the Senate : — ' (l) An enlarge- 

 ment of the powers directly exercised by Convocation ; (2) An 

 increase in the proportion of senators to be nominated or elected 

 by Convocation, and the limitation of the tenure of office in the 

 case of all senators to a term of years ; (3) The encouragement 

 of mature study and original research among the members of the 

 University, by the establishment of University lectureships, of 

 limited tenure, in different departments of learning and science ; 

 (4) The introduction into the constitution of the University of 

 such modifications as may remove all reasonable ground of com- 

 plaint, on the part of any of the affiliated colleges, with respect 

 to the absence of means for expressing opinion and giving advice 

 to the Senate on the examination regulations, and on the changes 

 proposed to be made therein from time to time. And that a 

 Special Committee of ten members of Convocation be appointed 

 to consider the above-mentioned proposals, and to report thereon 

 to Convocation as speedily as possible.' " 



The Entrance Science Scholarships in St Thomas's Hospital 

 have been awarded this year as follows : — The Scholarship of 

 60/. to Mr. Wansborough Jones, B.A. Oxon., and B.Sc, 

 London ; and that of 40/. to Mr. A. E. Wells. 



