INTRODUCTION 3 
perfectly preserved, and are usnally 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 Palacozoology 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, 
cephalopods, 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 
