354 



NA TURE 



[February 13, 1896 



A 



problem in insect physiology, the solution of which we are 

 anxiously awaiting. The mere possibility of being able to state 

 t he problem in its present form— apart from any question of the 

 adaptive value of the colouration — is a step forwards ; is an 

 i ncentive to further experiment, and this is the legitimate end 

 and aim of all scientific speculation. 



Were I to attempt, however, to pass from what has already 

 been accomplished to that which is yet awaiting investigation — 

 to the questions which rise on all sides as pressing for solution, 

 there would be no limit to this address. In view of the splendid 

 opportunities afforded by insects for treatment as living organisms 

 capable of revealing natural laws by skilled experimental 

 research, is it not pardonable if we sometimes give way to the 

 unphilosophic thought that the possession of chitinous exo- 

 skeletons by these creatures, whereby they lend themselves so 

 admirably for preservation as cabinet specimens, is an arrange- 

 ment expressly designed for the retardation of entomological 

 science ? The scientific workers at living insects in this country 

 are deplorably few as compared with those who devote themselves 

 to cabinet entomology. The one great desideratum of modern 

 biology is an experiment station where protracted observations 

 can be carried on year after year on living animals, each set of 

 experiments prompted by hypothesis and with the definite 

 object of answering some particular question in relation to 

 variability and inheritance, the nature of the action of the en- 

 vironment, the effect of selection, &c. This was a dream of 

 the late Dr. Romanes ; he has not lived to see it fulfilled, but if 

 it should be realised in our time our entomologists will, I 

 venture to hope, not be behind with suggested lines of work. 



If by way of comparison we now turn to that branch of the 

 subject in which the empirical method has hitherto almost ex- 

 clusively been employed, viz. the taxonomy of this same order 

 Lepidoptera, the results are most instructive. In view of the 

 immense body of facts, the number of named species and the 

 mass of published descriptive matter, I do not think I shall be 

 wrong if I say that the best energies of the acutest workers 

 have been concentrated on this subject from the middle of the 

 last century down to the present time. A record of nearly a 

 century and a half against the thirty odd years that have elapsed 

 since the introduction of the theoretical method into the biological 

 sciences. Is there any indication that all this work has brought 

 us nearer the " definite end " to which it was and is directed 

 — the natural classification of the Lepidoptera — to an extent 

 commensurate with the number of workers and the time bestowed 

 upon it ? It is only quite recently that any decided advance has 

 been made, and that through the work of Hampson, Comstock, 

 Chapman, Meyrick, and others. It cannot be said that we have 

 been waiting all these years for materials — for a few thousand 

 new species is one of the best "collected " groups in the whole 

 world of insects — in order that this sudden rush might be made. 

 I take the view that we have been waiting rather for method 

 than for additions to the lists of species ; that we have hitherto 

 too much disregarded the spirit of the speculative method in 

 our taxonomic work, and that we have now happily found a 

 band of workers who refuse to submit to the plea of inability 

 because all the existing species of Lepidoptera have not been 

 collected and named. 



After advancing these arguments in favour of a more liberal 

 use of the "scientific imagination" in connection with ento- 

 mological subjects, I feel it incumbent upon me to define the 

 position a little more fully in order to prevent misunderstand- 

 ing. The conditions of speculation in the two great depart- 

 ments of natural science which have been under consideration 

 are not exactly the same, and the differences in the method of 

 treatment must not be lost sight of. If in the physical sciences 

 there is, to use the expression of the late Prof. Stanley Jevons, 

 " unbounded license of theorising." it is because we can appeal 

 to nature so readily by the experimental method, and get our 

 answer one way or the other, by imposing rigid conditions which 

 are under our control. In the biological sciences this is not the 

 case ; all who are acquainted with experimental work in biology 

 know how difiicult it is, generally, to get definite answers to our 

 questions — the conditions are vastly more complex when we 

 come to deal with living organisms. I remember once remark- 

 ing to the late Mr. Darwin how difficult it was to get nature to 

 give a definite answer to a simple question, and he replied, with 

 a flash of humour : " She will tell you a direct lie if she can." 

 The practical result of this difference is that the speculation of 

 an hour may take a lifetime for its verification. But I see no 

 reason why, on these grounds, we should repress the spirit of 



NO. 1372, VOL. 53] 



speculation. If, as our former President says, it is given to few 

 to be able to speculate with advantage — and in this I thoroughly 

 agree with him — it is our paramount duty for the present and 

 future welfare of our science, to give every man's honest thought 

 our most serious attention, and to encourage the faculty when- 

 ever and wherever we find it, as the most precious means of 

 advancing scientific knowledge. The "bugbear" is a very 

 harmless animal if you look him boldly in the face, and if you 

 treat him gently and put him into harness he will drive the 

 chariot of science for you at a speed that will leave the empirical 

 method far behind in the race for the knowledge of nature's 

 ways. 



The great service which the founders of the modern doctrine 

 of evolution have rendered to science has, in my belief, been . 

 not only the particular theory of species transformation with 

 which their names will ever be associated, but the importation 

 into biology of the methods of the physical sciences. Writing 

 to Wallace, in 1857, Darwin said : "I am a firm believer that 

 without speculation there is no good and original observation " 

 (" Life and Letters," vol. ii. p. 108). In the same letter he 

 remarks: "You say that you have been somewhat surprised at 

 no notice having been taken of your paper in the Annals. 

 [" On the Law that has regulated the Introduction of New 

 Species," Ann. and Mag. Nat. Hist., 1855.] I cannot say 

 that I am, for so very few naturalists care for anything beyond 

 the mere descriptions of species." This statement of 1857 does 

 not hold good in 1896 ; other methods of biological research 

 have been introduced — the road to biological fame is no longer 

 through the sole channel of technical systematic work, and we 

 owe it to the writer of that letter more than to any other worker 

 and thinker of our time, that the horizon has been extended on 

 all sides. 



The misapprehension to which my remarks may possibly give 

 rise, and which I am most anxious to prevent, is that in urging 

 the claim of the theoretical method I am introducing the danger 

 of rash and promiscuous speculating by all kinds of dabblers in 

 the subject. There is much justification for this attitude, but 

 an analysis of the supposed danger will, I think, serve to show 

 that it is not a very formidable one after all. It appears to me, 

 moreover, that the advantage of giving an impetus to observation 

 along preconceived lines far outweighs any passing danger arising 

 from hasty speculation. It is notorious in the history of modern 

 science that no single branch has escaped the efforts of well- 

 intentioned, but quite irresponsible outsiders, to set our various 

 houses in order for us. On critical examination it will be found, 

 however, that none of these attempts, even when they have been 

 lucky enough to forestall the conclusions arrived at by legitimate 

 methods, have led to any practical issue in the way of observation 

 or research. I am addressing my remarks on the present occa- 

 sion to a Society composed more or less of experts ; I am not 

 inviting " the man in the street " to favour us with his views on 

 this, that, or the other question, but I am asking the working 

 entomologists among us to bear in mind that their studies may 

 be directed so as to throw light on some of the broad biological 

 problems of the day, if they will, as Faraday said, encourage 

 themselves by a little more speculation. Judging from the part 

 played by this method in the development of modern science, it 

 is perhaps not going too far to say that it is better to have, 

 speculated erroneously than never to have speculated at alls 

 Illustrations might be adduced showing that erroneous theorien 

 have often done good service to science, and that for this reasog 

 they have been temporarily retained, even when recognised ag 

 inadequate to meet the growing body of new evidence. Thi 

 was the case, for example, with the old " fluid " theory o 

 electricity. So also the "corpuscular" theory of light enabled 

 Newton to develop optical science to a remarkable extent, 

 although this theory is now among what Dr. Hicks calls the 

 "wreckage." 



Another source of danger in biological speculation to which I 

 am also alive, is that we have the public eye upon us to an 

 extent that is not experienced in other departments of science. 

 I am bound to confess that I nqver could quite make out why 

 this should be the case. It is possible to speculate about the 

 constitution of matter, the degradation of energy, the age of the 

 solar system, and other great problems of the universe, with any 

 degree of dogmatism without exciting public discussion. But 

 as soon as ever an effort is made to explain something in the 

 living world, no matter how modestly, the speculator is forth- 

 with treated as though he had thrown down a public challenge. 

 Perhaps it. is, for this reason that biology is more sub-ect to 



