464 



KNOWLEDGE 



[March 31, 1882. 



has raised somo interesting questions concerning the causes 

 and duration of changes in climate which permitted, now 

 nortl\ern spocius (as tlu! mammotb or woolly-haired elephant, 

 the musk shci'p, the reindeer, etc.) ; now southern spc^cics 

 (as the liippopotanius, liyana, lion, etc.), to roam over the 

 same ureas, finding at last a comuion grave. But to discuss 

 this at present would be to digress. 



The above outline of the leading contrasts between the 

 two Stone Ages may sullice to show that our subject lies 

 far beyond the historic horizon. Ordinary landmarks and 

 methods of reckoning, therefore, failing us, we can have 

 some idea of man's place in geological time only V)y ascer- 

 taining the relative position of those deposits in which 

 traces of him are belie\e(l to occur to the general system of 

 organic-bearing rocks. Such traces are in truth indicated 

 by what man has done, rather than by himself, for of him 

 scanty are the relics — only a jawbone or fibula (small leg- 

 bone) here, only a skull-fragment there, a paucity for 

 which we must hereafter seek an explanation. 



Vast as is the period in this world's history since the 

 appearance of man even iu Europe, it is Imt a fraction 

 compared with that which extends from the beginning of 

 life upon the earth to PaUeolithic times. Hreckel* remarks 

 that if we divide that period into a hundred equal parts, 

 and then, corresponding to the thickness of the systems of 

 strata, calculate the relative duration of the five main 

 divisions or periods according to percentages, we obtain the 

 following result : — 



Primordial Epoch .... 

 (70,000 feet.) 



Primary.. 



(42,000 feet.) 



Secondary 



(15,000 feet.) 



Tertiary . 



(3,000 feet.) 



Quaternary (or Pleistocene) 

 (500 or 700 feet.) t 



Laurcntian System 53"C 



Cambrian 



Silurian 



Devonian 32"1 



Coal 

 Permian 



Trias 11-5 



Jura 

 Chalk 



Eocene 2"3 



Miocene 



Pliocene 



Pateolithic Man ... 0'5 



Neolithic and 



Historical Period 



Now, it would be in defiance of all that the doctrine of 

 evolution teaches, and, moreover, win no support from 

 believers in special creation and the fixity of species, to 

 seek for so highly specialised a mammalian as man at an 

 early stage in the life-history of the globe. Even in the 

 Secondary epoch, the only mammals which have been dis- 

 covered in Europe are the fossil remains of a small 

 marsupial or pouch-bearer ; and although the placental 

 mammals and the order of Primates, to which man is 

 related, appear in Tertiary times, and the climate, tropical 

 in the Eocene age, warm in the ]\Iiocenc, and temperate 

 in the Pliocene, was favourable to his presence, the 

 proofs of his existence in Europe before the close of 

 the Tertiary epoch, although considered sufiicient by 

 many foreign savans, are not generally accepted here. 



It is at this point, however, that the interest of the matter 

 deepens. No anthropologist of repute denies the a priori 

 probability of man's presence in Europe under the favour- 

 able conditions of mid-Tertiary times ; and the remembrance 

 of what incredulity met the discovery in 1847 of relics 

 indisputably of human origin in hitherto undisturbed de- 

 posits in the Somnie Valley, checks incautious and hasty 

 treatment. Let us glance at the evidence on which the 

 French advocates of Miocene man now rest their case. Recog- 



• " Hist, ot Creation," vol. ii. p. 20. 



t The thicknesses of this and the other deposits are only approxi- 

 mately true. 



nising tho enormous duration of the Palaeolithic Age, onei 

 of the most eminent of their number, M. Gabriel del 

 Mortillet, has divided it into several well-marked stages,! 

 certainly with such warranty as all that we have at ha 

 in support of the slow rate of human advance gives, 

 these divisions, five in number, M. de Mortillet places 

 earliest in the mid-Miocene period. 



FOUND LINKS. 



By Dr Axdkew "Wilson, F.R.8.E., F.LS. 

 PAST IV. 



THERE are no two classes of animals between which 

 exists a greater dissimilarity than birds and reptile& 

 The active organisation of the one and the sluggish ways of 

 the other, the warm blood of the former and the cold blood 

 of the latter, are points in the popular natural history of 

 the two groups which technical zoology has but emphasised 

 in its turn. Yet the scientific examination of these beings 

 reveals bonds of connection between them, all unsuspected 

 by the ordinary reader, and demonstrates further, in the 

 most suggestive fashion, that the likenesses to be presently 

 alluded to must possess some origin and meaning. That 

 origin, evolution maintains, is " descent " from a common 

 stock ; the meaning is that seen throughout all similar 

 series of likenesses, namely, the natural result of the 

 laws of animal development. In the case of birds and 

 reptiles, the same considerations appeal to us which I have 

 already indicated as existent in the details of frog-develop- 

 ment. Either the likenesses science discovers between 

 apparently distinct groups of animals are explicable, or 

 they are not explicable. If the former, then science de- 

 clares, with unanimous voice, that the likenesses are due 

 to common descent, as the unlikenesses are due to the 

 variations and modifications produced during the evolution 

 of the race. If, on the other hand, the likenesses are inex- 

 plicable — as I hold them to be on any other theory save 

 that of evolution — then must mankind fold their hands in 

 the acknowledgment of an ignorance that might legiti- 

 mately, by its avowal, close the door to astronomical 

 research, to geological work, and to scientific investigation 

 of every kind. 



I am led to make these remarks because several corre- 

 spondents have remarked to the editor, that because like- 

 nesses can be proved to exist between two different groups of 

 animals in their young state, they do not understand why 

 the evolutionist should lay such stress upon these facts as 

 proving his contentions. One correspondent, for instance, 

 says that he cannot admit that because one thing is like 

 another, tlie two things must stand in the relation of parent 

 and offspring. I replj% likeness does not necessarily imply 

 similarity of origin, but, on the other hand, it is one of the 

 proofs of such similarity. If likeness is to be denied its 

 place as a proof of common origin — apart from other 

 and equally powerful proofs known to biologists — what 

 guarantee should we possess that unlikeness means dis- 

 similarity 1 That the likeness of child to parent 

 is a natural likeness, every one must admit. The 

 reasons are clear enough, and they derive thtir force 

 from the fact that the latter begets the former. I hold 

 that the likenesses existent — especially in the early 

 stages of development — between different groups, are to 

 be judged on the same basis, namely that of heredity. 

 A manifest resemblance in the young frog to a fish is, I 

 repeat, inexplicable, equally on scientific principles and 

 on common sense grounds, unless on the hypothesis that 

 some bond of relationship comiects the two. The duty of 



