434 



NATURE 



[August 22, 1907 



to ensure the production of one or other of the various 

 phases of the life-history. There are many fungi, for 

 example, which arc believed to represent vegetative stages 

 of Ascomycetes or Basidlomyccles, but it has not yet been 

 found possible to ascertain the conditions that would cause 

 them to form the highest fructifications. Even in simpler 

 instances a similar difficulty is sometimes encountered. 

 Thus Bispora monilifonne, a mould that often occurs on 

 the wood and stumps of oak or hornbeam, is not readily 

 cultivated as the Bispora form, whether it be grown on 

 Wood or on various nutritive media. The usual result of 

 raising it under artificial conditions is to obtain a luxuriant 

 crop of Eurotium-like mould. But the Bispora form can 

 be reproduced from such a culture by growing it in strong 

 solutions of cane sugar under certain conditions, all of 

 which are not as yet understood. 



I talce it we shall agree that the properties of structure 

 and form are to be interpreted as the necessary result of 

 the action of particular substances on the protoplasm, and 

 that these cause it to assume those definite attributes 

 which we term specific on account of their constancy 

 through a larger or smaller range of individuals. But 

 this constancy of form must then be the result of a 

 ■corresponding definiteness in the series of changes under- 

 gone by the raw materials supplied as food in their upward 

 transformations; each stage in the process limits the 

 possible range of those that follow, as in the case of the 

 ferments to which I have alluded ; and thus it becomes 

 increasingly diflicult to modify the final result. 



In this way wc may sec, perhaps, an explanation of the 

 circumstance that in amphibious plants the particular 

 structure, whether adapted for land or water, that will 

 arise in conformity with the environment is irrevocably 

 determined long before the organs themselves are 

 sufficiently developed to be exposed to the direct influence 

 of the conditions to which they are supposed to be specially 

 adapted. 



Now it is a matter of common knowledge that the 

 formative processes can be, and sometimes are, disturbed 

 with the most surprising results. I may again refer to 

 the fungal or insect galls as examples that will be familiar 

 to everyone. It appears to me that these exceptional 

 developments are of extraordinary importance in relation 

 to any endeavour to probe the mysteries of organisation. 

 The very difficulty experienced in imitating the effect of 

 the insect's secretion strongly emphasises the specialised 

 nature of the particular substance which is able to modify 

 the " normal " reactions of the plant. The latter are 

 dependent on the way in which the organic apparatus deter- 

 mines the fashion of the molecular presentations, so that, 

 as I have said, the course of the reactions themselves 

 become increasingly limited in their range. Now as re- 

 gards the manner in which the secretion of the insect 

 operates, it seems clear that it can produce no permanent 

 change in the organising apparatus of the protoplasm, 

 since the growth is at once arrested on the removal or 

 death of the insect. But whether the influence is one 

 that more directly affects the physical state of the apparatus 

 for the time being, or whether it acts more directly by 

 introducing new substances into the final chemical re- 

 actions, are questions which are plainly worth investi- 

 gation, but at present certainly do not admit of an answer. 



Another example of interference with the developmental 

 processes is afforded by the well-known " lithium larva," 

 which was discovered by Herbst to arise when the eggs 

 of some species of sea-urchins are allowed to segment in 

 sea-water that has been altered by the addition of lithium 

 salts. The monstrosity produced under these conditions 

 was just as constant and specific in character as are the 

 different galls which can be induced to develop on an oak 

 leaf by the corresponding species of insect. 



Extending these considerations a little further, one sees 

 that what we call disease also falls into the same cate- 

 gory. For disease represents the necessary outcome of a 

 disturbance, however introduced, into the course of meta- 

 bolism, which diverts it from the " normal " channels. 

 Pathology has long recognised that the explanation and 

 the consequent control of disease lies, ultimately, in the 

 correct appreciation of the cellular reactions as the result 

 of their experimental study. We cannot pride ourselves 

 on the advances that have been made in the studv of 



NO. 1973. VOL. 76] 



plant pathology as yet. Our remedies are commonly of 

 the crudest kind, and we have only recently begun to 

 take serious count of the facts of organisation in the 

 scientific attempt to breed races of plants immune from 

 the attack of certain diseases. The results that have 

 already been obtained, both abroad and by Biffen and 

 others in this country, are full of hope at the present 

 time. The study of the causes of immunity along scientific 

 lines ought assuredly to form a fruitful field of investi- 

 gation in the near future. 



From what we already know it seems clear that the 

 proximate causes of immunity may be diverse in character, 

 and may consist in very different reactions in different 

 cases. It may be that the response becomes expressed in 

 a modification of the carbohydrate metabolism, leading 

 to the formation of an excluding layer of cork ; or it may 

 lie in the direction of those substances, as yet so little 

 understood, the anti-toxins ; or, again, it may be due to 

 still other and even less apparent causes. But whatever 

 the true nature of the response, it will have to be investi- 

 gated for individual cases, and its secrets will only be 

 unlocked when the chemical and physical processes involved 

 in its operation are understood. 



In making these remarks I dare say I may be accused 

 of putting forward an impossible ideal, or at any rate one 

 that is impracticable of attainment. I am not very much 

 concerned about that. Progress is only to be made by 

 trying to penetrate further than we can at present see, 

 and I believe we have gained enough insight into the 

 chemistry and physics of the living processes to warrant 

 us in hoping that we shall penetrate a good deal deeper 

 still. But if we are to ever unravel the tangle, it can 

 only be by applying such methods as have been successful 

 in dealing with material things elsewhere. 



For the problems that rise up before us are seen, as . 

 we become able to get at close quarters with them, to 

 resolve themselves more and more into questions of 

 chemistry and physics. I believe that it is only by the 

 help of these elder branches of science that the accurate 

 formulation, to say nothing of the final solution, of the 

 problems will be achieved. A recent writer has suggested 

 that life is not the cause of the reactions underlying the 

 phenomena of life. Nevertheless the reactions that go on 

 in the living body are obviously guided as to the particular 

 directions they take by the apparatus or mechanism of 

 the individual organism. When the conditions for the 

 manifestation of life, and all that it implies, are satisfied, 

 what will be produced depends partly on the structure of 

 the apparatus itself (i.e., on the hereditary organisation), 

 partly on the nature of the substances fed into the 

 apparatus, and finally on the physical conditions under 

 which it is working. It is probably along the last two 

 lines that investigation will continue to be pursued with 

 more immediate profit ; but the goal will not be finally 

 reached until wo have solved the problem as to the nature 

 of organisation itself. 



SECTION L. 



F.DUC.\T!OX.1L SCIENCE. 



OrENixG .'\ddrf.ss uv Sir Philip M.\gnus, B.Sc, B.A., 

 M.P., President of the Section. 



The Application of Scientific Method to Educational 

 Problems. 



Notwithstanding the fact that the greater part of my 

 life has been spent in educational work, in teaching, in 

 examining, in organisation, and in the investigation of 

 foreign systems of instruction, I have experienced con- 

 siderable difficulty in selecting, from the large number of 

 subjects that crowd upon me, a suitable one on which 

 to address you as President of a Section of the British 

 .\ssociation devoted to educational science. 



At the outset I am troubled by the title of the section 

 over which I have the honour to preside. I cannot refrain 

 from asking myself the question. Is there an educational 

 Science, and if so, what is its scope and on what found- 

 ations does it rest? The object of the British Association 

 is the advancement of Science, and year by year new facts 

 are recorded in different branches of inquiry,, on which 

 fresh conclusions can be based. The progress of past 



