I 



Sept. 12, 1889] 



NATURE 



469 



Anyone who has closely followed these discussions, especially 

 those bearing most directly upon what is generally regarded as 

 the most important factor of evolution — natural selection, or 

 "survival of the fittest " — cannot fail to have noticed the appeal 

 constantly made to the advantage, the utility, or otherwise of 

 special organs, or modifications of organs or structures to their 

 possessors. Those who have convinced themselves of the 

 universal application of the doctrine of natural selection hold 

 that every particular structure or modification of structure must 

 be of utility to the animal or plant in which it occurs, or to some 

 ancestor of that animal or .plant, otherwise it could not have 

 come into existence ; the only reservation being for cases which 

 are explained by the principle which Darwin called "correlation 

 of growth." Thus the extreme natural selectionists and the old- 

 fashioned school of teleologists are so far in agreement. 



On the other hand, it is held by some that numerous structures 

 and modifications of structures are met with in Nature which are 

 manifestly useless ; it is even confidently stated that there are 

 many which are positively injurious to their possessor, and 

 therefore could not possibly have resulted from the action of 

 natural selection of favourable variations. Organs or modifi- 

 cations when in an incipient condition are especially quoted as 

 bearing upon this difficulty. But here, it seems to me, we are 

 continually appealing to a criterion by which to test our theories 

 of which we know far too little, and this (though often relied 

 upon as the strongest) is, in reality, the weakest point of the 

 whole discussion. 



Of the variations of the form and structure of organic bodies 

 we are beginning to know something. Our museums, when 

 more complete and better organized, will teach us much on this 

 branch of the subject. They will show us the infinite and 

 wonderful and apparently capricious modifications of form, 

 colour, and of texture to which every most minute portion of 

 the organization of the innumerable creatures which people the 

 earth is subject. They will show us examples of marvellously 

 complicated and delicate arrangements of organs and tissues in 

 many of what we consider as almost the lowest and most im- 

 perfectly organized groups of beings with which we are 

 acquainted. But as to the use of all these structures and 

 modifications in the economy of the creatures that possess 

 them, we know, I may almost say, nothing, and our museums 

 will never teach us these things. If time permitted I might 

 give numerous examples in the most familiar of all animals, 

 whose habits and actions are matters of daily observation, with 

 whose life-history we are as well acquainted almost as we are 

 with our own, of structures the purposes of which are still most 

 doubtful. There are many such even in the composition of our 

 own bodies. How, then, can we expect to answer such questions 

 when they i-elate to animals known to us only by dead specimens, 

 or by the most transient glimpses of the living in a state of 

 nature, or when kept under the most unnatural conditions in 

 confinement ? And yet this is actually the state of our knowledge 

 of the vast majority of the myriads of living beings which 

 inhabit the earth. How can we, with our limited powers of 

 observation and limited capacity of imagination, venture to 

 pronounce an opinion as to the fitness or unfitness for its 

 complex surroundings of some peculiar modification of structure 

 found in some strange animal dredged up from the abysses of 

 the ocean, or which passes its life in the dim seclusion of some 

 tropical forest, and into the essential conditions of whose 

 existence we have at present no possible means of putting our- 

 selves in any sort of relation ? 



How true it is that, as Sir John Lubbock says, "we find in 

 animals complex organs of sense richly supplied with nerves, 

 but the functions of which we are as yet powerless to explain. 

 There may be fifty other senses as different from ours as sound 

 is from sight ; and even within the boundaries of our own 

 senses there may be endless sounds which we cannot hear, and 

 colours as different as red from green of which we have no 

 conception. These and a thousand other questions remain for 

 solution. The familiar world which surrounds us may be a 

 totally different place to other animals. To them it may be full 

 of music which we cannot hear, of colour which we cannot see, 

 of sensations which we cannot conceive." 



The fact is that nearly all attempts to assign purposes to the 

 varied structures of animals are the merest guesses and 

 assumptions. The writers on natural history of the early part of 

 the present century, who " for every why must have a wherefore," 

 abound in these guesses, which wider knowledge shows to be 

 untenable. Many of the arguments for or against natural 



selection, based upon the assumed utility or equally assumed use- 

 lessness of animal and vegetable structures, have nothing more 

 to recommend them. In fact, to say that any part of the organ- 

 ization of an animal or plant, or any habit or instinct with which 

 it is endowed, is useless, or still more injurious, seems to me an 

 assumption which, in our present state of knowledge, we are not 

 warranted in making. The time may come when we shall have 

 more light, but infinite patience and infinite labour are required 

 before we shall be in a position to speak dogmatically on these 

 mysteries of Nature — labour not only in museums, laboratories, 

 and dissecting-rooms, but in the homes and haunts of the 

 animals themselves, watching and noting their ways amid their 

 natural surroundings, by which means alone we can endeavour 

 to penetrate the secrets of their life-history. But until that time 

 comes, though we may not be quite tempted to echo the despair- 

 ing cry of the poet, " Behold, we know not anything," a frank 

 confession of ignorance is the most straightforward, indeed the 

 only honest position we can assume when questioned on these 

 subjects. 



However much we may be convinced of the supreme value of 

 scientific methods of observation and of reasoning, both as mental 

 training of the individual and in the elucidation of truth and 

 advancement of knowledge generally, it is impossible to be blind 

 to the fact that we who are engaged with the investigation of 

 those subjects which are commonly accepted as belonging to the 

 domain of physical science are unfortunately not always, by 

 virtue of being so occupied, possessed of that most precious gift, 

 " a right judgment in all things." 



No one intimately acquainted with the laborious and wavering 

 steps of scientific progress (I can answer at least for one branch 

 of it) can look upon that progress with a perfect feeling of 

 satisfaction. 



Can it be said of any of us that our observations are always 

 accurate, the materials on which they are based always sufficient, 

 our reasoning always sound, our conclusions always legitimate ? 

 Is there any subject, however limited, of which our knowledge 

 can be said to have reached finality ? 



Or if it happens to any of us as to 



A man who looks at glass 



On it may stay his eye. 

 Or if he pleases through it pass 



And then the heavens espy, 



are not those heavens which are beyond the immediate objects 

 of our observation coloured by our prejudices, prepossessions, 

 emotions, or imagination, as often as they are defined by any 

 profound insight into the depth of Nature's laws ? In most of 

 these questions an open mind and a suspended judgment 

 appear to me the true scientific position, whichever way our 

 inclinations may lead us. 



For myself, I must own that when I endeavour to look beyond 

 the glass, and frame some idea of the plan upon which all the 

 diversity in the organic world has been brought about, I see the 

 strongest grounds for the belief, difficult as it sometimes is in the 

 face of the strange, incomprehensible, apparent defects in struc- 

 ture, and the far stranger, weird, ruthless savagery of habit, often 

 brought to light by the study of the ways of living creatures, 

 that natural selection, or survival of the fittest, has, among other 

 agencies, played a most important part in the production of the 

 present condition of the organic world, and that it is a universally 

 acting and beneficent force continually tending towards the 

 perfection of the individual, of the race, and of the whole living 

 world. 



I can even go further and allow my dream still thus to run :^ 



Oh yet we trust that somehow good 

 Will be the final goal of ill, — 



That nothing walks with aimless feet, 



That not one life shall be destroyed 



Or cast as rubbish to the void 

 When God hath made the pile complete. 



SECTION A. 



MATHEMATICS AND PHYSICS. 



Opening Address by Captain W. de W. Abney, C.B., 

 R.E., F.R.S., F.R.A.S., President of the Section. 

 The occupant of this chair has a difficult task to perform, 

 should he attempt to address himself to all the various subjects 

 with which this Section is supposed to deal. I find that it has 

 very often been the custom that some one branch of science 



