August x6, 1894] 



NATURE 



371 



SECTION D. 



Opening Address by Prof. I. Bayley Balfour, M.A., 

 M.D., F. R.S., President of the Section. 



The prospect of visiting Oxford to-day has, I am sure, been 

 to all of us a pleasant one, and we who are specially interested 

 in biology have looked forward to our meeting at this time with 

 the distinguished members of the Oxford Biological School. 

 But as we gather here there will, I think, be present to the 

 minds of all of us a thought of one member of that school, 

 whom we had hoped to meet, who is recently gone from it in 

 the prime of his intellectual life. By the death of George John 

 Romanes biological science is bereft of one of its foremost ex- 

 positors, Oxford is deprived too soon of one whose mental 

 power was yet in its zenith, and each one of us who knew him 

 cannot but feel a deep sense of personal loss ; and we shall in 

 onr meeting here sadly miss the man brimming with a geniality 

 which robbed differences of their difficulty and charmed away 

 bitterness from those controversies in which he revelled. This 

 is not the occasion upon which to dwell on his character, his 

 merits, or his work. We must all, I think, have appreciated 

 the graceful accuracy with which these were sketched in the pages 

 of Nature by one of his colleagues ; but under the shadow, as 

 we are here, of his recent death, I believe I give utterance to 

 feelings every one of you would wish expressed in paying this 

 passing tribute to his memory from the chair of the Section of 

 the Association devoted to the subject of his life-work. 



I cannot open the business of the Section without referring to 

 the fact that its organisation appears to be variable, like the 

 objects of its study. It has changed its constitution more than 

 any other Section of the Association, under influences partly 

 from within in the strength of its elements, partly from without 

 in the local circumstances of its meetings. At its origin it was 

 the Section of botany, zoology, anatomy, and physiology ; in 

 the following year anatomy and physiology became a new 

 Section, E, only after some years to merge again in the original 

 one. Then a partition was tried — a physiology department and 

 an anthropology department were formed within Section D; but 

 the Montreal meeting saw anthropology as Section H of the 

 Association, and physiology again an integral portion of Section 

 D. This year, as you are aware, physiology — -I must be careful 

 to say animal physiology — has again become a definite Section 

 — I. Whether or no the habit thus acquired through the 

 environment of Oxford will be so permanent as to be transmitted 

 and appear at future meetings of the Association is a problem 

 upon which I refrain from speculating ; my reason for men- 

 tioning this matter at all is to point out that, as in previous 

 devolutions of subjects from Section D, animal physiology 

 is the only physiology which is concerned. It was part 

 of the original proposal that plant physiology should form 

 a portion of the province of Section I. To this the botanical 

 members of Section D are unable to assent. We all readily 

 admit that the development within recent years of our know- 

 ledge of plant- life is entirely in the direction of bringing to light 

 fundamental similarities between the vital processes in plants 

 and in animals. To no one do we owe more in this sphere of 

 investigation than to two of the distinguished botanists from 

 Germany whom we are glad to welcome at this meeting — Profs. 

 Pfefier and Strasburger. And we fully reciprocate the desire 

 for mutual comment and criticism implied in the suggestion of 

 combinatiin. But allowing these as grounds for the conjoint 

 treatment of the physiology of plants and animals in one section, 

 what we botanists feel is ihat we are a compact body of workers 

 in a science the boundaries of which it is at present not difficult 

 to define, and that to divorce physiology from morphology and 

 other branches of botany would tend to loosen our cohesion, 

 would he 10 go against the current of our progress, and would 

 take all the vitality from our discussions. To have papers on 

 plant physiolcigy dealt with in Section I, whilst those on other 

 botanical subjects were dealt with in Stction D, would be not 

 merely an extremely inconvenient arrangement, from causes 

 inherent in the subjects themselves, but would strike at that 

 fraternity and spirit of camaraderie amongst those treading the 

 same paih of sci' nee, I he promotion of which is the chief, il not 

 the only, (unciion the British Association now fulfils. At the 

 outset, therefore, of our meetings, I wish to make it known that 

 papers and discussions on all botanical subjects will take place 

 in Section D. 



And now I pass to the special topic upon which I am to 

 address you. In selecting it I have followed the lead of those of 

 my predecessors in this chair who have used the opportunity to 

 discuss a practical subject. Forestry, about which I purpose 

 to speak, is a branch of applied science to which, in this 

 country, but little attention has been given by any class of the 

 community. By scientific men it has been practically ignored. 

 Yet it is a division of Rural Economy which ought to be the 

 basis of a large national industry. 



There are no intrinsic circumstances in the country to pre- 

 vent our growing trees as a profitable crop for timber as well as 

 our neighbours. On the contrary. Great Britain is specially 

 well adapted for tree-growing. We have woodlands of fine 

 trees, grown after traditional rule-of-thumb methods, abundant 

 in many districts. The beauty of an English landscape lies in 

 its trees and its pastures. Nowhere in the world, probably, are 

 to be found finer specimens of tree-growth. As arboriculturists 

 we are unrivalled. But the growing of trees for effect and in 

 plantations is a very different matter from their cultivation on 

 scientific principles, for the purpose of yielding profitable crops. 

 This is sylviculture. The guiding lines of the two methods of c ul- 

 ture are by no means the same — nay, they may be opposed ; and 

 it is the sylvicultural aspect of the science of forestry which has 

 hitherto been neglected in this country. The recognition of 

 this is no new thing. But within recent years it has attracted 

 considerable public attention, as the importance of wood culti- 

 vation in our national life has been more realised ; and although 

 various proposals have been put forward, and some little effort 

 made for the purpose of remedying the admittedly unsatisfactory 

 state of forestry practice, there has been so far no great result. 

 I attribute this in great measure to the apathy of scientific men, 

 especially botanists, and I am convinced that until they devote 

 attention to forestry the great issues involved in it will not be 

 rightly appreciated in the country. 



It is not the ftist time the subject has been before this 

 Section. I find thf.t in 1885, at the Aberdeen meeting, a com- 

 mittee was appointed by it to consider " whether the condition 

 of our forests and woodlands might not be improved by the 

 establishment of a forest-school." The good intention of the 

 promoters was not fulfilled, however. The committee did not 

 meet. 



In the first instance, let me briefly refer to the national 

 economic features of forests as they affect us. 



There are two aspects from which forests are of importance 

 to a country — firstly, as a source of timber and fuel ; secondly, 

 on account of their hygienic and climatic influences. 



With regard to the latter, it is a popular notion that trees 

 exercise considerable influence upon atmospheric conditions, 

 but it is only within recent years, and as the result of long 

 experimental research in Switzerland, France, Austria, Ger- 

 many, and other areas where forestry is practised at a high 

 level of excellence, and also in the United States, that any 

 sufficient data have been forthcoming to form a basis of scien- 

 tific conclusion upon so important a matter. Although many 

 points are still far from clear, the evidence goes to show that 

 the direct influence of tree-growth upon climate is no mere 

 superstition. Staled in the most general terms, it is proved 

 that forests improve the soil drainage, and thereby modify 

 miasmatic conditions ; whilst, like all green plants, trees exer- 

 cise, through the process of carbon-assimilation, a purifying 

 effect upon the air, the existence of the increased quantity of 

 ozone often claimed for the vicinity of forests is not yet estab- 

 lished ; by opposing obstacles to air currents, forests prevent 

 the dissemination of dust particles with their contingent germs ; 

 1 they reduce the extremes of temperature of the air ; they increase 

 the relative humidity of the air and the precipitation in rainfall, 

 and they protect and control the waterflow from the soil. 



To us these eff^ects do not appeal with the same force that 

 they do in continental areas. Our insular and geographical 

 position renders us in a measure independent of them. The 

 data for these continental results, it must be remembered, are 

 derived from large forest areas such as do not exist here. For 

 this country I know of no experimental evidence on the subject. 

 As, however, the effects of forest influence are (elt mainly in 

 local modifications of climatic conditions, we are not justified in 

 regarding the conclusions that have been reached as inapplic- 

 able to Britain. No little interest attaches, therefore, to a 

 statement based upon these continental observations to which 

 Dr. Nisbet has recently done well to call attention — that, 

 "where the rainfall is over forty inches it is undesirable to 



Nu. I 291, VOL. 50] 



