500 



NA TURE 



[September 24, 1896 



Nor is there any reason lo suppose that it will be otherwise in the 

 future, and I am not one of those who consider that the brilUant 

 discoveries were the exclusive reward of the pioneers in our 

 science, and that labourers of the present day must be contented 

 with the gleanings of their harvest ; on the contrary, the dis- 

 coveries which await the geologist will probably be as striking 

 as are those which he has made in the past. The onward 

 march of science is a rhythmic movement, with now a period 

 of steady labour, anon a more rapid advance in our 

 knowledge. It would perhaps be going too far to say that, 

 Tio far as our science is concerned, we are living in a period 

 rather of the former than of the latter character, though no 

 great geological discovery has recently affected human thought in 

 ^he way in which it was affected by the proofs of the antiquity 

 of man, and by the publication of "The Origin of Species." If, 

 however, we are to some extent gathering materials, rather than 

 drawing far-reaching conclusions from them, I believe this is 

 largely due to the great expansion which our science has under- 

 gone in recent years. It has been said that geology is "not so 

 .much one science, as the application of all the physical sciences 

 to the examination and description of the structure of the 

 ■earth, the investigation of the agencies concerned in the 

 production of that structure, and the history of their action " ; 

 and the application of other sciences to the elucidation of the 

 history of our globe has been so greatly extended of recent 

 years, that we are apt to lose sight of the fact that geology is in 

 itself a science, and that it is the special province of the geologist 

 to get his facts at first hand from examination of the earth. The 

 spectroscope and the telescope tell the geologist much ; but his 

 proper instrument is the hammer, and the motto of every 

 geologist should be that which has been adopted for the 

 Ceological Congress, Menic et iiialleo. 



At the risk of being compared to a child playing with edged 

 tools, I cannot help referring to the bearing of modern strati- 

 graphical research on the suggested replacement of a school 

 of uniformitarianism by one of evolution. The distinguished 

 advocate of Evolutionism, who addressed the Geological 

 Society in 1S69 upon the modern schools of geological thought, 

 spoke of the school of evolution as though it were midway 

 between those of uniformitarianism and catastrophism, as 

 indeed it is logically, though, considering the tenets of the up- 

 holders of catastrophism, as opposed to those of uniformi- 

 tarianism, at the time of that address, there is no doubt that 

 ■evolutionism was rather a modification of the uniformitarianism 

 of the period than intermediate between it and catastrophism, 

 which was then practically extinct, at any rate in Britain. One 

 •of my predecessors in this chair, speaking upon this subject, 

 says that " the good old British ship ' Uniformity,' built by 

 Hutton and refitted by Lyell, has won so many glorious victories 

 in the past, and appears still to be in such excellent fighting 

 trim, that I see no reason why she should haul down her 

 ■colours, either to ' catastrophe ' or ' evolution.' " It may be so ; 

 but I doubt the expediency of nailing those colours to the mast. 

 That Lyell, in his great work, proved that the agents now in 

 ■operation, working with the same activity as that which they 

 •exhibit at the present day, mii;ht produce the phenomena 

 ■exhibited by the stratified rocks, seems to be generally admitted, 

 but that is not the same thing as proving that they did so pro- 

 <luce them. Such proof can only be acquired by that detailed 

 examination of the strata which I have advocated in this address, 

 and at the time that the last edition of the "Principles" 

 appeared, our knowledge of the strata was far less complete 

 than it has subsequently become. It appears to me that we 

 should keep our eyes open to the possibility of many phenomena 

 presented by rocks, even newer than the Archa;an rocks, having 

 been produced under different conditions from those now preva- 

 lent. The depths and salinity of the oceans, the heights and 

 extent of continents, the conditions of volcanic action, and many 

 other things may have been markedly different from what they 

 are at present, and it is surely unphilosophical to assume condi- 

 tions to have been generally similar to those of the present day, 

 on the slender data at our disposal. Lastly, uniformitarianism, 

 in its strictest sense, is opposed to rhythmic recurrence of 

 events. " Rhythm is the rule with nature ; she abhors uni- 

 formity more than she does a vacuum," wrote Prof Tyndall, 

 many years ago, and the remark is worth noting by geologists. 

 Why have we no undoubted signs of glacial epochs amongst 

 the strata from early Ctmbrian times to the Great Ice 

 Period, except in Permo-Carboniferous times ? Is there not 

 an apparent if not a real absence of minifestation of volcanic 



NO. 1404, VOL. 54] 



activity over wide areas of the earth in Mesozoic times? 

 Were not Devonian, Permo-Triassic, and Miocene times 

 periods of mountain-building over exceptionally wide areas, 

 whilst the intervening periods were rather marked by quiet 

 depression and sedimentation ? A study of the evidence 

 availaljle in connection with questions like these suggests 

 rhythmic recurrence. Without any desire to advocate hasty 

 departure from our present methods of research, I think it 

 should be clearly recognised that evolution may have been an 

 important factor in changing the conditions even of those times 

 of which the geologist has more direct knowledge. In this, as 

 in many other questions, it is best to preserve an open mind ; 

 indeed, I think that geologists will do well lo rest satisfied 

 without an explanation to many problems, amongst them the 

 one just referred to ; and that working hypotheses, though 

 useful, are better retained in the manuscript notebooks of the 

 workers than published in the Trainailions of Learned 

 Societies, whence they filter out into popular works, to the 

 great delight of a sceptical public should they happen lo be 

 overthrown. 



May I trespass upon your patience for one moment longer .' 

 As a teacher of geology, with many years' experience in and out 

 of a large University, I have come to the conclusion that 

 geology is becoming more generally recognised as a valu- 

 able instrument of education. The memory, the reasoning 

 faculties, and the "powers of observation are alike quickened. 

 The work in the open air, which is inseparable from a right 

 understanding of the science, keeps the body in healthy 

 condition. But over and above these benefits, the communing 

 with nature, often in her most impressive moods, and the 

 insignificance of events in a man's lifetime, as compared with 

 the ceaseless changes through the long ceons which have gone 

 before, so influence man's moral nature, that they drive out his 

 meaner thoughts and make him " live in charity with all men." 



SECTION D. 



ZOOLOGY. 



OrENiNc, Address by Prof. E. B. Poui.ton, E.R.S., 

 President ok the Section. 



A very brief study of the proceedings of this Section in 

 byegone years will show that Presidents have exercised a very 

 wide choice in the selection of subjects. At the last meeting 

 of the Association in this city in 1870 the Biological Section 

 had as its President the late Prof. Rolleston, a man whose 

 remarkable personality made a deep impression upon all who 

 came under his influence, as I have the strongest reason for 

 remembering, inasmuch as he was my first teacher in zoology, 

 and I attended his lectures when but little over seventeen. His 

 address was most characteristic, glancing over a great variety ol 

 subjects, literary as well as scientific, and abounding in quotations 

 from several languages, living and dead. A very dift'erent style 

 of address was that delivered by the distinguished zoologist who 

 presided over the meeting. Prof. Huxley took as his subject 

 "The History of the Rise and Progress of a Single Biological 

 Doctrine. " 



Of these two types I selected the latter as my example, and 

 especially desired to attempt the discussion, however inadequate, 

 of some difliculty which confronts the zoologist at the very out- 

 set, when he begins to reason from the facts around him — a 

 difficulty which is equally obvious and of equal moment to the 

 highly-trained investigator and the man who is keenly interested 

 in Ihe results obtained by others, but cannot himself lay claim to 

 the position and authority of a skilled observer — lo the naturalist 

 and to one who follows some other branch of knowledge, but is 

 interested in the progress of a sister science. 



Two such difficulties were alluded to by Lord Salisbury in his 

 interesting presidential address to the British .-Association at 

 Oxford in 1894, when he spoke of "two of the strongest 

 objections lo the Darwinian explanation " of evolution — viz. the 

 theory of natural selection — as appearing "still to retain all 

 their force. " The first of these objections was the insufficiency 

 of the time during which the earth has been in a habitable slate, 

 as calculated by Lord Kelvin and Prof Tail, 100 million years 

 being conceded by the former, but only 10 million by the latter. 

 Lord Salisbury quite rightly stated that for the evolution of the 

 organic world as we know it by the slow process of natural 

 selection at least many hundred million years are required ; 



