September 30, 1920] 



NATURE 



161 



Fossils and Life.* 

 By F. A. Bather, M.A., D.Sc, F.R.S. 



I PROPOSE to consider the relations of palaeonto- i 

 logy to the other natural sciences, especially the j 

 biological ; to discuss its particular contribution to \ 

 biological thought ; and to inquire whether its facts 

 justily certain hypotheses frequently put forward in 

 its name. If 1 subject those attractive speculations 

 to cold analysis, it is from no want of admiration, or 

 even sympathy, for in younger days I too have 

 sported with N'italism in the shade and been caught ] 

 in thi- tangles of Transcendental hair. 



Ihe Differentia of Palaeontology. 



Paljeontology is often regarded as nothing more 

 than the botany and zoology of the past. True, the 

 general absence of any soft tissues and the obscured 

 or fragmentary condition of those harder parts which 

 alone are preserved make the studies of the palaeonto- 

 logist more difficult, and drive him to special methods. 

 But the result is less complete ; in short, an inferior 

 and unattractive branch of biology. Let us relegate 

 it to Section C ! 



Certainly the relation of palseontology to geology 

 is obvious. It is a part of that general history of the 

 earth which is geology. To the scientific interpreter 

 of earth-history the importance of fossils lies, first, in 

 their value as date-markers, and, secorKlly, in the 

 '■ ' r which they cast on barriers and currents, on 

 inal and climatic variation. Conversely, the 

 iii-i.iry of life has itself been influenced by geologic 

 change. But all this is just as true of the present 

 inhabitants of tfie globe as it is of their predecessors. 

 It does not give the differentia of palaontology. 



That which above all distinguishes paheontology, the 

 stud) of ancient creatures, from neontology, the study 

 of creatures now living, that which raises it above the 

 mere description of extinct assemblages of life-forms, 

 i=! the concept of Time. The bearing of this obvious 

 ment will appear from one or two simple illus- 

 ins. 



Effect of the Time-concept on Principles of 

 Classification. 



\ilopting the well-tried metaphor, let us imagine 

 Jhc tree of life buried except for its topmost twigs 

 beneath a sand-dune. The neontologist sees only the 

 unburied twigs. He recognises certain rough group- 

 ings, and constructs a classification accordingly. 

 From various hints he may shrewdly infer that some 

 twigs come from one branch, some from another, but 

 th<' relations of the branches to the main stem are 

 Bi.itters of speculation, and when branches have 

 become so interlaced that their twigs have long been 

 lubj<-cted to the same external influences he w-ill 

 )r<)bably b<- led to incorrect conclusions. TIh- palseon- 

 [ologist then comes, shovels away the sand, and by 

 legrecs exposes the true relations of branches and 

 t»-igs. His work is not yet accomplishe<l, and 

 mrobably he never will reveal the root and lower part 

 Sbf the free, but already he has corrected many 

 Pintural, if not inevitable, errors of the neontologist. 



f * * * 



■'•Effect of the Time-concept on Ideas of Relationship. 

 S Etienne Geoflroy-Saint Hilaire wa,s the first to 

 "" pare the embryonic stages of certain animals with 

 adult stages of animals considered inferior. The 

 a grew until if was crv'stallined by the poetic 



I* Oinn'ng »lrfri!^a of i>>« froklcnl r.f S»clion C (r.eoloty), dali'md at 

 ^_ C»fdiff Meeting of lh« llrtti.h A«*ocbtion on Ausutt 14. Grtally i 

 ridgvd. Only Ihe largtr excision* are mdicatcd by attariftk*. 



NO. 2657, VOL. 106] 



imagination of Haeckel in his fundamental law of 

 the reproduction of life, namely, that every creature 

 tends in the course of its individual development to 

 pass through stages similar to those passed through 

 in the history of its race. This principle is of value 

 if applied with the necessary safeguards. If it was 

 ever brought into disrepute, it was ow-ing to the 

 reckless enthusiasm of some embryologists who un- 

 warrantably extended the statement' to all shapes and 

 structures observed in the developing animal, such 

 as those evoked by special conditions of larval exist- 

 ence, sometimes forgetting that every conceivable 

 ancestor must at least have been capable of earning 

 its own livelihood. Or, again, they compared the early 

 stages of an individual with the adult structure of 

 its contemporaries instead of with that of its pre- 

 decessors in time. 



Such errors were beautifully illustrated in those 

 phylogenetic trees which, in the 'eighties, everv dis- 

 sector of a new or striking animal thought it his duty 

 to plant at the end of his paper. The trees have 

 withered because they were not rooted in the past. 



.A similar mistake was made by the palaeontologist 

 who, happening on a new fossil, blazoned it forth as 

 a link between groups previously unconnected — and in 

 too many cases unconnected still. This action, natural 

 ami even justifiable under the old purelv descriptive 

 system, became fallacious when descent was taken 

 as the basis. 



The so-called "generalised types," combining Ihe 

 features of two or three classes, and the " annectant 

 tvpes," supposed to unite lines of descent which l.ad 

 diverged many ages before, are conceptions still with 

 us. But thev are hopelessly inconsistent with any 

 genealogy either proved or probable. 



.\s bold suggestions calling for subsequent proof 

 these speculations had their value, and they mav be 

 forgiven in the neontologist, if not in the palaeonto- 

 logist, if we regard them as erratic pioneer tracks 

 blazed through a tangled forest. .\s our .-icquaintance 

 with fossils enlarged, the general direction became 

 clearer and certain paths were seen to be impossible. 

 In 1881, addressing this .Xssociation at York, Huxley 

 could sav : " Fifty years hence, whoever undertakes • 

 to record the progress of palaeontology will note the 

 present time as the epoch in which the law of suc- 

 cession of the forms of the higher animals was defer- 

 mined by the observation of palaontological facts. 

 He will point out that, just as Steno and aj Cuvier 

 were enabled from their knowledge of the empirical 

 laws of co-existence of the parts of animals to con- 

 clude from a part to a whole, so the knowledge of 

 the law of succession of forms err powered their suc- 

 cessors to conclude, from one or two terms of such 

 a succession, to the whole series, and thus to divine 

 the existence of forms of life, of which, perhaps, no 

 trace remains, at epochs of incnnccivabk; remoteness 

 in the past." 



Descent not a Corollary of Succession. 



Note that lluxley siioke of succession, not of 

 descent. Succession undoubtedly was recognised, but 

 the relation between the terms of the succession was 

 little understoo<l, and there was no proof of descent. 

 Ixt us suppose all written records to be swept away 

 and an attempt made to reconstruct English history 

 from coins. \Ve could set out our monarchs in true 

 order, and we might susp<'rt that the throne was 

 hereditary; but if on that assumption we were to 



