INTRODUCTION 3 



and botanical classifications. Notwithstanding all their difFerences, their 

 general structure is similar to that of recent organisms, and their Identification 

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

 The methods of paleontological research do not differ from those employed 

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

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

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

 is, nevertheless, incumbent on the paleontologist 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 characters, but must be extended to the finer microscopic and 

 histological as well. In numerous instances paleontology has anticipated 

 zoology and botany by important histological discoveries ; in the brauch 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 paleon- 

 tologists (Cuvier, Owen, Huxley, H. von Meyer, Rütimeyer, Marsh, Cope, 

 Osborn 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 organ 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 invertebrates 

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

 plate, carapace, shell-fragment and the like, is sufficient for us to form a 

 tolerably accurate concept of the entire creature. It is therefore clear that 

 in so far as paleontology 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 Paleozoology and Faleo- 

 lotany. Paleontology has vastly increased the subject - matter of the two 

 biological sciences, has filled up innumerable 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 preserva- 

 tion is possible, the number of fossil forms cohsiderably exceeds the recent. 

 A natural Classification of the Foraminifera, sponges, corals, echinoderms, 

 moUusks, vertebrates, and of the vascular cryptogams, cycads and conifers, 

 would be utterly inconceivable without taking paleontological evidence into 

 account, since in certain classes (brachiopods, cephalopods, reptiles, mammals) 

 the number of extinct fossil forms may be ten, a hundred, or even a thousand- 

 fold greater than the living, and this proportion is steadily increasing in 

 favour of paleontology, as fresh discoveries are made in various parts of the 

 World. 



Paleontology and Geology. — Although as a biological science paleon- 

 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 obtain 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 detritus on dry land by aerial agency. The distribution of fossils 

 throughout stratified rocks is by no means promiscuous, neither do all rocks 



