29' 



NATURE 



\Fcb. II, 1S75 



but their number and the number of subdivisions have greatly 

 increased. In 1822, when Phillips and Conybeare wrote tlieir 

 ' Geology of England and Wales,' twenty-three so-called forma- 

 tions were recognised, whereas now thirty-eight such are esta- 

 blished, and these arc divided into about 120 subdivisions, each 

 characterised by some peculiarity of structure or of fauna. 

 PaUxontology as a separate science was not then known ; struc- 

 tural and physical geology had chiefly occupied attention ; but 

 the study of organic remains has since advanced with such rapid 

 and vigorous strides that the older branch was until lately in 

 danger of being neglected and distanced, 



"At that time the number of species of organic remains in 

 Great Britain which had been described amounted only to 752, 

 whereas now the number amounts to the large total of 13.276 

 species. 



" Some idea of the extent and variety of the past life of our 

 globe may be formed by comparing these figures with the numbers 

 of plants and animals now living in Great Britain. Excluding 

 those classes and families, such as the naked mollusca and others, 

 which from their soft and gelatinous nature decay rapidly, and 

 so escape fossilisation, and insects * — the preservation of which 

 is exceptional — the number of living species amounts to 3,989, 

 against 13,183 extinct species of the same classes. 



" Thus, while the total nunilier of those classes of vertebrate and 

 invertebrate animals and plants represented in a fossil state, and 

 now living in Great Britain, is only 3,989, there formerly lived 

 in the same area as many as 13,276 species, so that the fossil 

 exceed the recent by 9,287 species. It must be remembered also 

 that plants are badly represented, for, owing to their restricted 

 prcser\'ation, the fossil species only number 823 against 1,820 

 recent species. Birds are still worse represented, as only eighteen 

 fossil species occur against 354 recent species. 



" But the multiplicity of British fossils, however surprising as a 

 whole, has to be viewed in another and different light. The 

 large total represents, not as the recent species do, the life of one 

 period, but the sum of those of all the geological periods. 

 Geological periods, as we construct them, are necessarily arbi- 

 trary. The whole geological series consists of subdivisions, each 

 one of winch is marked by a certain number of characteristic 

 species, but each having a large proportion of species common 

 to the .subdivisions above and below it. These various subdivi- 

 sions are again massed into groups or stages, having certain 

 features and certian species peculiar to them and common 

 throughout, and which groups are separated from the groups 

 above and below by greater breaks in the continuity of life and 

 of stratification than mark the lesser divisions. As these on the 

 whole severally exhibit a distinct fauna and flora, we rnay con- 

 veniently consider them as periods, each having its own distinc- 

 tive life, and the number of which in Great Britain we have taken 

 approximately at thirty-eight. 



" The number of species common to one period and another 

 varies very greatly, but taking the average of the sixteen divi- 

 sions ol the Jurassic and Cretaceous series, of which the lists 

 were, with a portion of those of the older series, given a few 

 years since by Prof. Ramsay, t we may assume that about thirty 

 per cent, of the organic remains pass from one stage to another. 



"Dividing the 13,276 fossil species among the thirty-eight 

 stages, or omitting the lower stages and some others, and taking 

 only thirty, we thus get an average of 442 species for each ; and, 

 allowing in addition for the number common to every two 

 periods, we obtain a mean of 630 species as the population of 

 each of the thirty periods, against the 3,989 species of the 

 present period. On this view the relative numbers are therefore 

 reversed. 



" This gives a ratio for the fauna or flora of a past to that of the 

 present period of only as I : b'3. But it must be remembered 

 that probably the actual as well as the relative numbers of the 

 several classes inter si in each and all of these several formations, 

 varied greatly at the different geological periods. Still we have 

 no reason to suppose but that during the greater part of them 

 life of one form or another was as prolific, or nearly so, in the 

 British area then as at the present day, and we may thus form 

 some conception of how little relatively, though so much really, 

 w-e have yet discovered, and of how much yet remains to be 

 done Ijefore we can re-establish the old lands and seas of 

 each successive period, with their full and significant populations. 

 This we cannot hope ever to succeed in accomplishing fully, for 



The number of British species of insects amounts to between : 



Dand 



t Anniversary Addresses for 1863 and 1864. Quarterly journal Geolo- 

 gical Society. The tables were computed by Mr. iLtheridge. 



decay has been too quick and the rock entombment too much 

 out of our reach ever to yield up all the varieties of past life ; 

 but although the limits of the horizon may never be reached, the 

 field may be vastly extended ; each segment of that semicircle 

 may yet be prolonged we know not how far ; and it is in this 

 extension — in the filling up of the blanks existing in the life 01 

 each particular period— that lies one great work of the future." 

 {To be continued.) 



NOTES 



It is perhaps too much yet to expect any allusion to the 

 interests of science in that very staccato composition, a Queen's 

 Speech. The next best thing to this, however, occurred last 

 Friday, when Lord Rayleigh, the seconder of the Address, very 

 courageously pointed out the omission from the Speech of any 

 allusion to an event "which had excited some public interest of 

 a non-political character." His lordship referred to the recent 

 Transit of Venus, in which the astronomers of this country had 

 taken a part, but by no means, he thought, "too large a 

 pait." We confess that on this point we quite agree with 

 Lord Rayleigh ; indeed, we think he has stated the case, as 

 against England in this matter, with remarkable mildness. But 

 this is a mere detail compared with what followed. Lord Ray- 

 leigh said " he could not pass from astronomy without expressing 

 a hope that other sciences of equal philosophical interest and greater 

 material importance might receive more Government recognition 

 than had hitherto been accorded them. It was something of an 

 anomaly that England, whose great prosperity was largely due 

 to scientific invention, should be slow to encourage those 

 whose discoveries were laying the foundations of future progress. 

 It was said, he knew, that these things might be safely left to 

 individual enterprise, but there were fields of investigation in 

 which individuals were powerless. We hope that this emphatic 

 advocacy of the claims of science on Government, by one who 

 has had tlie honour of being selected to second the Address on 

 the Queen's Speech, augurs favourably for the amount of attention 

 these claims ore likely to secure during the forthcoming session. 



The words of Mr. Disraeli on Monday night with regard to 

 University Reform are also very cheering to those who wish to 

 see some decided action taken towards the thorough reform of 

 our Universities. Mr. Disraeli's words were very strong, so 

 strong indeed as to amount to an assurance that Government 

 really means to take into serious consideration this session the 

 Report of the University Commi'sion. "It is our opinion," the 

 Prime Minister said, " that no Government can exist which for a 

 moment maintains that the consideration of University Reform, 

 and consequently legislation of some kind, will not form part of 

 its duty." These words give out no uncertain sound. Mr. 

 Disraeli said, moreover, that when the Report was presented at 

 the end of last session, the Colleges were not assembled. It 

 would be interesting to know whether the Colleges have yet met 

 to consider the Report, and whether they are likely to act on this 

 hint of the Premier and take some internal action — commence 

 the work of reform from within, instead of waiting until they are 

 driven to it by forces from without. 



We are able to give this week the first instalment of an 

 abstract of Prof. Freslwich's lecture in the chair of Geology 

 at Oxford. We have printed it in small type, in order to be 

 able to give as much as possible of an address which, our readers 

 will see, is likely to mark an important stage in the history of 

 geological science. The address will shortly be published in 

 a separate form. 



The Arctic Committee appointed by the Admiraltj', having 

 completed its work and sent in a final report, was dissolved last 

 week. The Committee has got through much work in the way 



