REVIEWS. 
29 / 
yet revealed to us, of pliints of the most complex organisation, is very 
striking, for not a single dicotyledonous angiosperm has yet been found in 
any primary formation, and only one undoubted monocotyledon, although 
these two great divisions taken together form four-fifths of our living vege- 
tation.” Further, he points out that though conifers, cycads, and ferns 
existed in abundance in the Triassic, Oolitic, and Lower Cretaceous periods, 
the plants which now characterise our flora seem not to have come into 
existence, or to have been extremely rare, before the Upper Cretaceous epoch. 
Turning to the animal kingdom. Sir Charles is equally forcible in his 
observations. He is by no means carried away by the theory, but carefully 
examines the facts, and in doing so shows us that the argument from the 
successive groups of fossil mollusca is of little use to the progressive evolu- 
tionist. On the whole,” he says, it cannot be said that the successive 
development in the course of past ages, of higher and more complex struc- 
tures, is by any means conspicuous in that grand branch of the animal 
kingdom which is most largely represented in a fossil state.” Not so, 
however, with vertebrates. The failure of the palaeontologist to detect a 
single bone of any aquatic vertebrate animal, in rocks older than Mur- 
chison’s Ludlow formation is a fact of no small weight in favour of pro- 
gressive development.” The difficulty presented in the instance of the 
Ganoid fishes, which appeared first, and whose organisation appears to be of 
a higher order than that of the Teleostei, is not overlooked, but Sir Charles 
calls attention to these important points : — (1) That the persistent character 
of the notochord of these fishes is a mark of degradation, and (2) that the 
possession of a heterocercal tail is an indication of the retention of an em- 
bryonic condition, or, in general terms, a sort of arrest of development. In 
speaking of the class of reptiles. Sir Charles refers to the very important 
fact that some of the fossil groups are of a higher order than the types now 
in existence, so that we have in this instance, an example of a class which 
gradually advanced till it reached a culminating point from which it has 
ever since been retrograding.” So, on the author travels through the birds 
and mammalia, till he comes to the monkey of the Eocene, Aretocyon pri- 
mcBvus, He finally draws a decided conclusion in the following lines : — 
We have been fairly led, by palaeontological researches, to the conclusion 
that the invertebrate animals flourished before the vertebrate, and that in 
the latter class, flsh, reptiles, birds, and mammalia, made their appearance in 
a chronological order, analogous to that in which they would be arranged 
zoologically, according to an advancing scale of perfection in their 
organisation.” 
Of the other new points in the edition, we may refer to the author’s 
examination (Chap. XI.) of the proofs of former vicissitudes in climate, 
derived from the study of secondary and primary fossiliferous formations ; and 
also to the thirteenth chapter, which is nearly entirely new, and in which 
he discusses the very remarkable theories as to changes of climate which 
have recently sprung up in connection with the suggestions of astronomers 
as to variations in the eccentricity of the earth’s orbit, changes in the 
obliquity of the ecliptic, and various phases of the precession of the 
equinoxes. In this chapter the author does ample justice to the specula- 
tions of Mr. Croll. Finally, we would refer to the large amount of additional 
