INTRODUCTION 3 



perfectly preserved, and are usually more or less altered in appearance, yet, on 

 the whole, they readily fit into place in the great framework of the zoological 

 and botanical classifications. Notwithstanding all their differences, they are 

 built on the same general plan as recent organisms, and their identification 

 requires the most careful comparison with nearly related plants and animals. 

 The methods of palaeontological research do not differ from those employed* 

 by the zoologist and botanist, excepting, of course, that the palaeontologist is 

 restricted to those parts alone which are capable of preservation, and must 

 reconstruct the missing soft parts ideally from analogy with recent forms. It 

 is, nevertheless, incumbent on the palaeontologist to obtain all possible informa- 

 tion from the material such as it is, aided by every means he can devise ; and 

 hence his investigations do not cease with an examination of the external, 

 macroscopic characteristics, but must be extended to the finer microscopic and 

 histological as well. In numerous subdivisions of the animal and vegetable 

 kingdoms, palaeontology has anticipated zoology and botany by important 

 histological discoveries ; in the branch of vertebrate comparative anatomy, for 

 example, through the exhaustive study of conservable hard parts, such as the 

 teeth, skeleton, dermal covering, etc., this science has been elevated to its present 

 high standard chiefly by palaeontologists (Cuvier, Owen, Huxley, H. v. Meyer, 

 Riitimeyer, Marsh, Cope, and others). The principle of correlation of parts, first 

 applied with such eminent success by Cuvier, according to which all parts of an 

 organism stand in certain fixed relationships to one another, so that one part 

 cannot vary without a corresponding variation taking place in the others, is 

 now worked out not only for the whole group of vertebrates, but for inverte- 

 brates as well ; and its elaboration is such that frequently a single bone, tooth, 

 or plate, a sadly demolished carapace, a shell-fragment, a bit of stem, and the 

 like, is sufficient for us to form a tolerably accurate conception of their former 

 owner. It is therefore clear that in so far as palaeontology has to deal with 

 the study and classification of fossil organisms, it is no other than a part of 

 zoology, comparative anatomy, and botany, and hence may be very properly 

 divided into Palaeozoology and Palaeobotany. Palaeontology has astonishingly 

 increased the subject-matter of the two biological sciences, has filled up in- 

 numerable gaps in the system, and has infinitely enriched our knowledge of the 

 variety and complexity of plant and animal organisation. In almost every class 

 of both kingdoms where preservation is possible, the number of fossil forms 

 considerably exceeds the recent. A natural classification of the Foraminifera, 

 sponges, corals, echinoderms, mollusks, vertebrates, and of the vascular crypto- 

 gams, cycads, and conifers, would be utterly inconceivable without taking 

 palaeontological evidence into account, since in certain classes (brachiopods, 

 cephalopocls, reptiles, mammals) the number of extinct fossil forms is ten, a 

 hundred, or even a thousand-fold greater than the living, and this proportion is 

 steadily increasing in favour of palaeontology, since new fossiliferous localities 

 are being discovered almost daily in various parts of the world. 



Palaeontology and Geology. Although as a biological science palaeon- 

 tology does not differ essentially from botany and zoology, yet its connection 

 with geology is none the less intimate, and consequently it has been cultivated 

 quite as assiduously by geologists as by biologists. The material is brought to 

 light almost wholly by geologists or by geological collectors, who derive it 

 from the stratified rocks of the earth's crust that is to say, rocks which have been 

 formed by the subaqueous deposition of sediment, or have been built up from 



