PROFESSOR HUXLEY'S LECTURES. 209 



through to the present day. Such is the case with the Globigerince, 

 the skeletons of which, aggregated together, form the great mass of 

 our chalk in England. That Globigerina can be traced down to the 

 Globigerince which live at the surface of onr great oceans, and the 

 remains of which, falling to the bottom of the sea, give rise to a 

 chalky material. So that it must be admitted that certain species of 

 creatures living at the present day show no sign of modification or 

 transformation in the course of a lapse of time as great as that which 

 carries us back to the period of chalk. There are groups of species 

 so closely allied together that it needs the eye of a naturalist to dis- 

 tinguish them one from another. If we pay attention to these, we 

 find that a vastly greater period must be allotted, in some cases, to 

 these persistent forms. In the chalk itself, for example, there is the 

 fish belono-ing to the highest and the most differentiated of osseous 

 fishes, which go by the name of JBeryx. That fish is one of the most 

 beautiful of fossils found in our English chalk. It can be studied 

 anatomically, so far as the hard parts are concerned, almost as well as 

 if it were a recent fish. We find that that fish is represented at the 

 present day by very closely-allied species which are living in the 

 Pacific and Atlantic Oceans. But we may go still farther back, and 

 we find, as I mentioned to you yesterday, that the Carboniferous for- 

 mations in Europe and in America contain the remains of scorpions 

 in an admirable state of preservation, and those scorpions are hardly 

 distinguishable from such ns now live. I do not mean to say that 

 they are not distinguishable, but they require close scrutiny to distin- 

 guish them from the scorpions which exist at the present day. 



More than that. At the very bottom of the Silurian series, in 

 what is by some authorities termed the Cambrian formation, where 

 all signs of life appear to be dying out even there, among the few 

 and scanty animal remains which exist, we find species of molluscous 

 animals which are so closely allied to existing forms that at one time 

 they were grouped under the same generic name. I refer to the well- 

 known Lingula of the Lingula flags, lately, in consequence of some 

 slight differences, placed in the new genus IAngulella. Practically it 

 belongs to the same great generic group as the Lingula, which you 

 will find at the present day upon the shores of Australia. And the 

 same thing is exemplified if we turn to certain great periods of the 

 earth's history as, for example, throughout the whole of the Meso- 

 zoic period. There are groups of reptiles which begin shortly after 

 the commencement of this period, as the Ichthyosauria and the Ple- 

 siosauria, and they abound in vast numbers. They disappear with 

 the chalk, and throughout the whole of that great series of rocks they 

 present no important modifications. Facts of this kind are undoubt- 

 edly fatal to any form of the doctrine of evolution, which necessitates 

 the supposition that there is an intrinsic necessity on the part of 

 animal forms which once come into existence to undergo modifica- 



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