112 



NA TURE 



[December i, 1898 



digested and erroneous matter that cumbers the pages of modern 

 scientific journals. Here it is that you specially need patience. 

 Before you venture to publish anything, take the utmost pains to 

 satisfy yourselves that it is true, that it is new, and that it is 

 worth putting into print. And be assured that this reticence, 

 while it is a kindness to the literature or .science, will most 

 certainly bring with it its own reward to yourselves. It will 

 increase your confidence, and make your ultimate contributions 

 more exact in their facts as well as more accurate and convincing 

 in their argument. 



The other danger to which I referred as demanding patience 

 is of an opposite kind. As we advance in our career, and the 

 facts of our investigations accumulate around us, there will come 

 times of depression when we seem lost in a labyrinth of detail 

 out of which no path appears to be discoverable. We have, 

 perhaps, groped our way through this maze, following now one 

 clue, now another, that seemed to promise some outlet to the 

 light. But the darkness has only closed around us the deeper, 

 and we feel inclined to abandon the research as one in which 

 success is, for us at least, unattainable. When this blankness 

 of despair shall come upon you, take courage under it, by 

 remembering that a patient study of any department of nature is 

 never labour thrown away. Every accurate observation you have 

 made, every new fact you have established, is a gain to science. 

 You may not for a time see the meaning of these observations, nor 

 the connection of these facts. But their meaning and connection 

 are sure in the end to be made out. Vou have gone through the 

 labour necessary for the ascertainment of truth, and if you 

 patiently and watchfully bide your time, the discovery of the 

 truth itself may reward your endurance and your toil. 



It is by failures as well as by successes that the true ideal of 

 the man of science is reached. The task allotted to him in life 

 ■is one of the noblest that can be undertaken. It is his to 

 penetrate into the secrets of nature, to push back the cir- 

 cumference of darkness that surrounds us, to disclose ever 

 more and more of the limitless beauty, harmonious order, and 

 imperious law that e.xtend throughout the universe. And while 

 he thus enlarges our knowledge, he shows us also how nature 

 may be made to minister in an ever augmenting multiplicity of 

 ways to the service of humanity. It is to him and his conquests 

 that the material progress of our race is mainly due. If he 

 were content merely to look back over the realms which he has 

 subdued, he might well indulge in jubilant feelings, for his 

 peaceful victories have done more for the enlightenment and 

 progress of mankind than were ever achieved by the triumphs 

 of war. But his eye is turned rather to the future than to the 

 past. In front of him rises the wall of darkness that shrouds 

 from him the still unknown. What he has painfully accom- 

 plished seems to him but little in comparison with the infinite 

 possibilities that lie beyond. And so he presses onward, not 

 self-satisfied and exultant, but rather humbled and reverential, 

 yet full of hope and courage for the work of further conquest 

 that lies before him. 



Such is the task in which you may be called to share. When 

 you have entered upon it and have learnt something of its trials 

 and responsibilities, as well as of its joys and rewards, you will 

 look back with gratitude to the training you received within the 

 walls of this College. Vou will feel even more keenly than you 

 do now how much you owe to the patient kindness and educa- 

 tional skill of your teachers and to the healthy stimulus of con- 

 tact and competition with your class-fellows. Most heartily do 

 I wish you success in your several careers. Following up the 

 paths which have been opened for you here, may it be yours to 

 enlarge still further the circle of light which science has gained, 

 and to wrest from nature new aids for the service of mankind. 



THE BRITISH ASSOCIATION. 



BRISTOL MEETING. 



Sectio.n' K (Botany). 



Opening Address bv I'rok. F. O. Bower, Sc.D., F.R.S., 



Presides I of the Section.' 



III. 



T^HE following considerations influence me in forming an 



■*■ opinion as to the real place of apospory and apogamy in 



the history of the alternating generations : — 



I. The Bryophylesshow remarkable uniformity of alternation : 

 1 Continued from p. 91. 



NO. 1 518, VOL. 59] 



irregularities are few ; apogamy is not recorded ; apospory 

 appears rarely, as a physiological refuge for the destitute plant. 

 This uniformity goes along with the protected and dependent 

 condition of the sporophyte. All Pleridophytes have their em- 

 bryos protected while young, and this seems to have been their 

 primitive condition. The true lesson of the Bryophyta, which 

 include the simplest living Archegoniates, seems thus to be that 

 uniformity of alternation goes with a simple structure, and a pro- 

 tected or dependent condition of the sporophyte ; and this we 

 have reason to believe was the condition of the simpler Arche- 

 goniate fruits. 



II. The distribution of apogamy and apospory among .\rche- 

 goniates at large is very irregular ; the Leptosporangiate Ferns 

 are the headquarters ; but they are a peculiarly specialised 

 phylum, with free sporophyte, exposed when mature, though 

 protected while young. They are adapted to special conditions 

 and show a greater plasticity of development than any other 

 Pteridophytes. The Ferns are subject to other abnormalities 

 than apospory and apogamy. The root may develop directly 

 into a shoot, or the apex of the leaf into a bud. I think it has 

 been too readily held that the Ferns occupy a special place as 

 a key to the morphological problem. We should bear in mind 

 how really isolated they are ; they are essentially an extreme, 

 even an extravagant type ; they show the largest sporophylls in 

 the whole vegetable kingdom, with the largest numerical output 

 of spores from each. Many are specialised in accordance with 

 extreme conditions of shade and moisture. These consider- 

 ations .should temper our view of them, not only as material foi 

 normal comparison, but also as exponents of abnormality. 



III. The fact that jin cases of induced apogamy in Ferns 

 archegonia are first produced, clearly shows that in these cases 

 the first intention of the plant is towards a normal production of 

 embryos, while 'apogamy takes its place as a substitutionary 

 growth. It may remain an open question how far direct 

 apogamy will bear a similar interpretation. 



I\'. The character of the aposporous and apogamous growths 

 is very anomalous ; their position is not definite ; aposporous 

 growths may arise from the sorus and sporangia, or from the 

 most varied points on the margin or surface of the leaf. With 

 regard to apogamy in Ferns, it appears, as the result of a large 

 number of observations, that though there is an average normal 

 of position, still any one part of the sporophyte — stem, leaf, 

 ramentum, root, sporangium, or even tracheid — may arise, inde- 

 pendently of others, from the prothallus. Single sporangia, or 

 groups of them, may appear without vegetative organs of the 

 sporophyte ; leaves without other parts ; in one case, I believe, 

 as many as ten roots have been seen without any other members 

 of the sporophyte ! The close similarity of the parts thus 

 irregularly placed to those formed in regular sequence in the 

 normal plant should be a warning of their abnormality. I cannot 

 see in them any suggestion of a primitive state. Dr. Lang tells 

 me that these exceptional developments form only a small pro- 

 portion of the individuals in any one culture ; still they are 

 there, and those who hold that apogamous developnwnts are a 

 suitable basis for morphological argument must not pick and 

 choose those cases which suit their views, but miisl take even 

 the most extravagant into careful estimation. My own view is 

 that these anomalous growths are not a safe guide to past 

 history. But looked upon as the result of a recently acquired 

 transition from one generation already established to the other, 

 following nuclear changes, in the one ca-se of reduction after 

 insufficient nutrition, in the other of doubling of the chromo- 

 somes following on plethora, apospory and apogamy are at least 

 intelligible. We shall understand how the transition may take 

 place at one point or at many, while the irregularity of the 

 parts produced offers no morphological difficulty ; it is rather 

 what might have been anticipated if the transition were a ready 

 consequence of the conditions we have noted. 



I-astly, a word on Dr. Scott's utilitarian argument. He re- 

 marks, "a mode of growth which affords a perfectly efficient 

 means of abundant propagation cannot, I think, be dismissed as 

 merely teratological." We must be clear that utility is no 

 certain evidence of antiquity. As refuges for the physiologically 

 destitute, apogamy and apospory may play an important part 

 ti<nv, and in so far are not to be dismissed as mere freaks of 

 nature. But in my view they would rank, as regards utility pui 

 and simple, » ith the formation of adventitious buds on the root 

 system of a Poplar that has been felled ; or with the bulbils 

 which replace the flowers in so many mountain species ; neither 



