September 26, 1895] 



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jjenera. If we go on in this way we shall have to invent a new 

 Linn*us, wipe out the past, and begin all over again. 



Although I have brought the matter before the Section it is 

 not one in which this, or indeed any collective assembly of 

 botanists, can do very much. While I hope I shall carry your 

 assent with the general principles I have laid down, it must be 

 admitted that the technical details can only be ajjpreciated by 

 experienced specialists. All that can be hoiked is a general 

 agreement amongst the staffs of the principal institutions in 

 different countries where systematic botany is worked at ; the 

 free-lances must be left to do as they liUe. 



PL'BLICATIONS. 



I have dwelt at such length on certain aspects of my subject 

 that perhaps, without great injustice, you may retort on me the 

 complaint of one-sidedness But when I survey the larger field 

 of botany in this country, the prospect seems to me so va.st that 

 I should tlespair even if I had my whole address at my disposal 

 of doing it justice. I think that its extent is measured by the 

 way in which the publications belonging to our subject are main- 

 tained. First of all we have access to the Royal Society, a 

 privilege of which I hope we shall always continue to take 

 advantage for communications which either treat of fundamental 

 subjects, or at least are of general interest to biologists. Next 

 to this we have our ancient Linnean Society, with a branch of 

 its publication.s handsomely and efficiently devoted to systematic 

 work. Then we have the Annals of Botauy, which has now, I 

 think, established its position, and which brings together the 

 chief morphological and physiological work accomplished in the 

 country. Lastly, we have the Jotiriial of Botany, a less 

 ambitious but useful periodical, which is mainly devoted to the 

 labours of English botanists. I remember there was a time when 

 I thought that this, at any rate, was an exhausted field. But it 

 is not so ; knowledge in its most limited aspects is inexhaustible 

 if the labourer have the necessar)' insight. The discoveries of 

 Mr. Arthur Bennett amongst the potamogetons of the Eastern 

 Counties is a striking and brilliant instance. 



Besides the publication of the Annals we owe to the Oxford 

 Press a splendid series of the best foreign text-books issued in 

 our own language. If the thought has sometimes occurred to 

 one's mind that we were borrowers too freely from our in- 

 defatigable neighbours, I, at least, remember that the late Prof. 

 Eichler paid us the compliment of saying that he i>referred to 

 read one of these monumental books in the English translation 

 rather than in the original. I believe it is no secret that botany 

 owes the aid that Oxforil has rendered it in these and other 

 matters in great measure to my old friend the Master of 

 Pembroke College, than whom I believe science has no more 

 <levoted supporter. 



PaI..1!OBOTANV. 

 I have said much of recent botany ; I must not pass over that 

 of past ages. Two notable workers in this field have passed 

 away since our last meeting. Saporta was w ith us at Manchester, 

 and we shall not readily f'irget his personal charm. If some of 

 his work has about it a too imaginative character, the patience 

 and entire sincerity with which he traced the origin of the exist- 

 ing forms of vegetation in Southern Euro])e to their ancestors in 

 the not distant geological past w ill always deserve attentive study. 

 But in the venerable, yet always useful, Williamson we lose a 

 figure whose memory we shall long preserve. With rare instinct he 

 accumulated a wealth of material illustrative of the vegetation of 

 the Carboniferous epoch, which, I suppose, is unique in the 

 world. And this was prepared for examination with incom]xir- 

 able |>atience either by his own hands or under his own eyes. 

 He illustrated it with absolute fidelity. And if he did not in 

 describing it always use language with which we could agree, 

 nothing could ruffle either his imperturbable good nature or the 

 noble simplicity of his character. Truth to tell, we were often 

 in friendly warfare w ith him. But I rejoice to think that before 

 his peaceful end came he had patiently reconsidered and 

 abandoned all that we regarded as his heresies, but which were, 

 in truth, only the old manner of looking at things. -Vnd I think 

 that if anything could have contributed to make his departure 

 happy, it was the conviction that the comi)lelion of his work and 

 his scientific reputation would remain ]ierfectly secure in the 

 hands •■<" !>r '^•■■itt. 



Vegktabi.e Physiology. 



Turning again to the present, the difficulty is to limit the 

 choice of topics on which I would willingly dwell. In an 



address which I delivered at the Bath meeting in lS88, I 

 ventured to point out the important part which the action of 

 enzymes would be found to play in plant metabolism. My 

 expectations have been more than realised liy the admirable 

 work of Prof, (ireen on the one hand, and of Mr. Horace 

 Brown on the other. The wildest imagination could not have 

 foreseen the developments which in the hands of animal 

 physiologists would spring from the study of the fermentative 

 changes produced by yeast and bacteria. These, it seems to me, 

 bid fair to revolutionise our whole conceptions of disease. The 

 reciprocal action of ferments, developed in so admirable a 

 manner by Marshall Ward in the case of the ginger-ljcer plant, 

 is destined, I am convinced, to an expansion scarcely less 

 im|X)rtant. 



But, ))erhaps, the most noteworthy feature in recent work is 

 the disposition to reopen in every direction fundamental 

 questions. And here, I think, we may take a useful lesson from 

 the practice of the older Sections, and adopt the plan of 

 entrusting the investigation of sjiecial problems to small 

 committees, or to indinduals who are willing to undertake the 

 labour of reporting upon special questions which they have 

 made peculiarly their own. These reports would be printed in 

 exienso, and are capable of rendering invaluable ser\ice by 

 making accessible acquired knowledge which could not be got al 

 in any other way. 



We owe to Sir. Blackman a masterly demonstration of the 

 fact, long believed, but never, perhaps, properly proved, that 

 the surface of plants is ordinarily impermeable to gases. Mr. 

 Dixon has brought forw*ard some new views about water-move- 

 ment in plants, which I confess I found less instructive than 

 many of my brother botani.sts. They are expressed in language 

 of extreme technicality ; but, as far as I understand them, they 

 amount to this. The water moving in the plant is contained in 

 capillary channels ; as it evaporates at the surface of the leaves 

 a tensile strain is set up, as long as the columns are not broken, 

 to restore the original level. I can understand that in this way 

 the "transpiration current " may be maintained. But what I 

 want to know is how this explains the phenomena in the sugar 

 maple, a single tree of which will yield, I believe, 20-30 gallons 

 of fluid before a single leaf is expanded. 



We owe to Messrs. Darwin and .\cton the supply of a 

 " Manual of Practical \egetable Physiology," the want of which 

 has long been keenly felt. Like the father of one of the 

 authors, "I love to exalt plants" ('• QS). I have long lieen 

 satisfied that the facts of vegetable physiology are capable of 

 being widely taught, and are not less significant and infinitely 

 more convenient than most of those which can be easily 

 demonstrated on the animal side. How little any accurate 

 knowledge of the subject has extended was conspicuously 

 demonstrated in a recent discussion at the Royal Society, when 

 two of our foremost chemists roundly denied the existence of 

 a function of respiration in plants, because it was unknown to 

 Liebig ! 



Assimilation. 



The greatest and most fundamental problem of all is that of 

 assimilation. The very existence of life upon the earth 

 ultimately <lepends upon it. The veil is slowly, but I think 

 surely, lx;ing lifted from its secrets. We now know that starch, 

 if its first visible product, is not its first result. We are pretty 

 well agreed that this is what I have called a " proto- 

 carbohydrate. " How is the synthesis of this effected? Mr. 

 Acton, whose untimely end we cannot but deeply deplore, made 

 some remarkable researches, which were communicated to the 

 Royal Society in 1889, on the extent to which |)lants could take 

 advantage of organic compounds made, so to speak, ready to 

 their hand. Loew, in a remarkable jiaper, which will perhaps 

 attract less attention than it de.serves from being published in 

 Jaiian {Bull. College of Agrk. Imp. Univ. Tokio, vol. i. ), has 

 from the study of the nutriti' m of Ijacteria, arrived at some general 

 conclusions in the same direction. Bokorny appears recently 

 to have similarly experimented on alga;. Neither writer, how- 

 ever, seems to have been acquainted w ith Acton's work. The 

 general conclusion which I draw from Loew is to strengthen the 

 belief that form-aldehyde is .actually one of the first steps of 

 organic synthesis, as long ago suggested by Adolph Baeyer. 

 Plants, then, will avail themselves of ready-made organic 

 compounds which will yield them this Ixjdy. That a sugar can 

 be constructed from it has long been known, and Bokorny has 

 shown that this can l>e utilised by plants in the production of 

 starch. 



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