2o6 DESIGN IN NATURE 



still further back. I have referred to the fact, that the Carboniferous formations, in Europe and in America, con- 

 tain the remains of scorpions in an admirable state of preservation, and that those scorpions are hardly distinguish- 

 able from such as now live. More than this. At the very bottom of the Silurian series, in beds which are by some 

 authorities referred to the Cambrian formation, where the signs of Hfe begin to fail us— even there, among the 

 few and scanty animal remains which are discoverable, we find species of molluscous animals which are so closely 

 aUied to existing forms that, at one time, they were grouped under the same generic name. The same truth is 

 exemplified if we turn to certain great periods of the earth's history— as, for example, the Mesozoic epoch. There are 

 groups of reptiles, such as the Ichthyosauria and the Plesiosauria, which appear shortly after the commencement 

 of this epoch, and they occur in vast numbers. They disappear with the chalk and, throughout the whole of the 

 great series of Mesozoic rocks, they present no such modifications as can safely be considered evidence of progressive 

 modification. 



" Facts of this land are undoubtedly fatal to any form of the doctrine of evolution which postulates the sup- 

 position that there is an intrinsic necessity, on the part of animal forms which have once come into existence, to 

 undergo continual modification ; and they are as distinctly opposed to any view which involves the beUef that 

 such modification as may occur, must take place, at the same rate, in all the different types of animal or vegetable 

 hfe. There is another order of facts belonging to the class of negative or indifferent evidence. The great group 

 of lizards, which abound in the present world, extends through the whole series of formations as far back as the 

 Permian, or latest Palseozoic, epoch. These Permian lizards differ astonishingly httle from the hzards which exist 

 at the present day. Comparing the amount of the differences between them and modern hzards, with the pro- 

 digious lapse of time between the Permian epoch and the present age, it may be said that the amount of change is 

 insignificant. If the doctrine of evolution be true, it follows that, however diverse the different groups of animals 

 and of plants may be, they must all, at one time or other, have been connected by gradational forms ; so that, 

 from the highest animals, whatever they may be, down to the lowest speck of protoplasmic matter in which life 

 can be manifested, a series of gradations, leading from one end of the series to the other, either exists or has existed. 

 But when we look upon hving Nature as it is, we find a totally different state of things. We find that animals and 

 plants fall into groups, the different members of which are pretty closely allied together, but which are separated 

 by definite, larger or smaller breaks, from other groups. At the present time, for example, there are numerous 

 forms of non-ruminant pachyderms, or what we may call broadly the pig tribe, and many varieties of ruminants. 

 These latter have their definite characteristics, and the former have their distinguishing peculiarities. But there 

 is nothing that fills up the gap between the ruminants and the pig tribe. Such also is the case in respect of the 

 minor groups of the class of reptiles. In the existing fauna, the group of pig-like animals and the group of 

 ruminants are entirely distinct ; but one of the first of Cuvier's discoveries was an animal which he called the 

 Anoplotheriimi, and which proved to be, in a great many important respects, intermediate in character between 

 the pigs on the one hand, and the ruminants on the other. Another remarkable animal restored by the great 

 French palaeontologist, the Pahvotherinm, similarly tended to connect together animals to all appearance so different 

 as the rhinoceros, the horse, and the tapir. Subsequent research has brought to light multitudes of facts of the same 

 order. Instead of dealing with these examples, which would require a great deal of tedious osteological detail, 

 I take the case of birds and reptiles ; groups which, at the present day, are so clearly distinguished from one another 

 that there are perhaps no classes of animals which, in popular apprehension, are more completely separated. Exist- 

 ing birds are covered with feathers ; their anterior extremities, specially and peculiarly modified, are converted 

 into wings, by the aid of which most of them are able to fly ; they walk upright upon two legs ; and these limbs, 

 when they are considered anatomically, present a great number of exceedingly remarkable peculiarities. On the 

 other hand, existing reptiles have no feathers. They may have naked skins, or may be covered with horny 

 scales, or bony plates, or with both. They possess no wings ; they neither fly by means of their fore-limbs nor 

 habitually walk upright upon their hind-hmbs ; and the bones of their legs present no such modifications as we 

 find in birds. As we trace the history of birds back in time, we find their remains, sometimes in great abundance, 

 throughout the whole extent of the Tertiary rocks ; but, so far as our present knowledge goes, the birds of the Tertiary 

 rocks retain the same essential characters as the birds of the present day. Not very long ago no remains of birds 

 had been found below the Tertiary rocks. But, in the course of the last few years, such remains have been dis- 

 covered in England ; though, unfortunatel}'', in so imperfect and fragmentary a condition, that it is impossible to say 

 whether they differed from existing birds in any essential character or not. In America the development of the 

 Cretaceous series of rocks is enormous ; the conditions under which the later Cretaceous strata have been deposited 

 are highly favourable to the preservation of organic remains, and the researches carried on by Professor Marsh have 

 rewarded him with the discovery of the forms of birds of which we had hitherto no conception. By his Idndness 

 I am enabled to place before you a restoration of one of these extraordinary birds, every part of which can be 



