October 3, 1901J 



NATURE 



557 



No. 3737 Skostinsky gives observations made at Pulkowa on 

 the aureole and spectrum. The lines given are as follows : — 



Elements of Co.met 1901 I. — Mr. C. J. Merfield publishes 

 the computed elements of the orbit of this comet in Astro- 

 nomische Nachrichteii (Bd. 1 56, No. 373S). The reductions 

 are from observations made by Mr. J. Tebbutt on 1901 May 3, 

 II and 19. 



T = 1901 April 24-22532 G3r.T. 



48 46) 

 46 23 Vic 

 = 131 2 35 J 



= 202 



= 109 46 23 



log '/ = 9-3873832 

 log e = 9 •9983750 



T//£ GLASGOW MEETING OF THE BRITISH 



ASSOCIATION. 



SECTION K. 



BOTANY. 



Opening Address by Prof. I. B.\yley B.alfour, LL.D. 

 (Glasg. ), F.R.S., President of the Section. 



I SHOULD be wanting in my duty, alike to you and to our 

 science, were I at the outset of our proceedings to pass over 

 without notice the circumstances of environment in which we 

 assemble to-day. In this, the first year of the century, our 

 Section meets for the first time in Scotland, and finds itself 

 housed in this magnificent Botanical Institute, which, through 

 the energy and devotion of Prof. Bower, has been added this 

 year to the equipment of Botany in this country. A few months 

 ago the Institute was opened in the happiest auspices and with 

 all the distinction that the presence of our veteran botanist. 

 Sir Joseph Hooker, supported by two other ex-Presidents of the 

 Royal Society — Lord Lister and Lord Kelvin — could give to the 

 ceremony. I am sure we will cordially echo the words of good- 

 will that were spoken on that occasion. It must be to all of 

 us a matter of congratulation that Botany has now provided for 

 it in Glasgow this Institute both for its teaching and for the in- 

 vestigation of its inner secret=, and we may with confidence hope 

 that the output of valuable additions to our knowledge of plant- 

 life which has marked Glasgow during the tenure of office of ils 

 present distinguished Professor of Botany, and in which he 

 himself has borne so large a share, will not only continue but 

 will increase in a ratio not incommensurate with the facilities 

 that are now provided. 



The subject of my address is the group of Angiosperms. I 

 will speak generally of some points in their construction from 

 the point of view of their position as the dominant vegetation of 

 the earth's surface at the present time, and more particularly of 

 their relationship to water, as it is one which has much to do 

 with their holding the position they now have. I wish, how- 

 ever, in the first place to refer to 



The Communal Organisation of Angiosperms. 

 No fact of the construction of the plant-body that has been 

 established within recent years is of greater importance than that 

 of the continuity of protoplasm in pluricellular plants. .\5 has 

 been the case with so many epoch-making discoveries, we owe 

 our first knowledge of this to the work of a British botanist. The 

 demonstration by Gardiner of the existence of intercellular proto- 

 plasmic connections is the foundation of our modern notion of the 

 constftution of the pluricellular plant-body and of the far-reaching 

 conception of the communal organisation of Angiosperms and 

 of all other Metaphyta.' It has settled, once and for all, 



1 Metaphyta and its antonym Protophyta are well-established names 

 for groups of polyergic and monergic plants respectively. The recent 

 appropriation of Metaphyta .-is a group name for Vasculares, i.e. plants 

 derived from the second antithetic generation, and of Protophyta for 

 Cellulares, i.e. plants derived from the first antithetic generation, is 



NO. 1666, VOL. 64] 



phytomeric hypotheses. We now realise that in an Angiosperm 

 the living plurinucleated protoplasm is spread over a skeletal 

 support furnished by the cell-chambers of shoot and root. The 

 energid of each living cell is connected with the adjacent 

 energids by the protoplasmic threads piercing the separating 

 cell-membrane. The protoplasm thus forms a continuous whole 

 in the plant. According to their position in the organism the 

 energids become devoted to the formation of special tissues for 

 the building up of the various organs. Each one of them, how- 

 ever, whilst its actual destiny is ultimately determined by its 

 relationships to the others, is, so long as its fate as a permanent 

 element is not fixed, a potential protophyte, that is to say, it has 

 within it all the capacities of the plant-organism to which it 

 belongs. 



Their construction out of this assemblage of protophytes — this 

 colonial, or perhaps better communal, organisation — gives to 

 Angiosperms their power of discarding effete and old parts of 

 the plant-body without mutilation, of allowing these to pass out 

 of the region of active life yet to remain without damage to the 

 organism as part of the body, of renewing and replacing 

 members as required. The response of the plant to the various 

 horticultural operations of pruning, propagation by cuttings, and 

 so forth is an outcome of this constitution. It is this which 

 gives them the power of developing reproductive organs at any 

 part of the plant-body, to cast them off when their work is done, 

 and to renew them again and again. This dispersion of the re- 

 productive capacity in the Angiosperm is one of the most striking 

 of the properties it possesses, and is perhaps in no way better 

 shown than in the development of stool-shoots. There the 

 energids of the cambium, which normally produce the permanent 

 tissue of wood and bark, and thereby add periodically to the 

 girth of a tree, give origin when the relationships are changed 

 by the cutting over of its bole to a callus from which stool- 

 shoots arise as new growths, which may ultimately produce 

 flower and reproductive organs. 



Another outcome of this organisation of the Angiosperm is its 

 power of extension and its longevity. It is potentially immortal. 

 How far this expectation of life of a plant is realised in nature 

 we have no evidence to show. Possibly we may presage the 

 longest life in the case of perennial herbs. Trees and shrubs by 

 their exposure in the air are liable to injury which must militate 

 against long life, and yet cases of trees of great age are well 

 known to you all. 



It is this feature of the life of Angiosperms which marks them 

 out sharply in contrast with the higher members of the animal 

 kingdom. There we have individuality, and consequently com- 

 paratively short life. Let me emphasise this. 



Of the Vegetable Kingdom and the Animal Kingdom. 



The root-difference between plants and animals is one of 

 •nutrition. Plants are autotrophic, animals heterotrophic. 



Whatever has been the origin of the two kingdoms, we must 

 trace the differentiation of plants to their acquisition of chloro- 

 phyll as a medium for the absorption of the energy of the sun. 

 The imprint of its operation is borne in the construction of all 

 higher plants and distinguishes them from animals. The vege- 

 tative mechanism of the plant has been elaborated upon lines 

 enabling it to obtain the materials of its food from gases and 

 liquids which it absorbs from its environment. For the plant 

 the primary requisite has been a sufficient surface of exposure in 

 the medium whence it could obtain energy along with the gases 

 and liquids of its food. To this end the fixed habit is an obvious 

 advantage, for the question of bulk within the limits of nutrition 

 becomes thereby not a matter of moment ; and an upward and a 

 downward extension gives opportunity for the creation of a 

 larger expanse of absorptive surface. Thus it has come about 

 that the plant-organism, has; developed that polarity which finds 

 expression in the profuse root-system and shoot-system with 

 their localised growing points of the highest forms of to-day. 

 That the communal organisation is well fitted to this mode ot 

 life requires no exposition. 



The nutritive mechanism of animals, on the other hand, has 

 become one for the ingestion of solids which it obtains by prey- 

 ing upon the bodies of plants and other animals. The exigencies 

 of its feeding have compelled the adoption by the animal of the 

 habit of locomotion, the development of an apparatus for the 

 capture of its prey, and of an alimentary canal for its introduc- 

 tion to the body, for its digestion, and for the final ejection of 

 the unused matter along with the waste of the body. This has 



