were placed in cabinets as objects of curiosity; but of late years 
geology, by uniting itself to chemistry, zoology and comparative 
anatomy, has gained a truly scientific position, and has pointed out 
that fossil remains at all periods must have been constructed by the 
same laws that now regulate animal creation, and that the more ancient 
faunas are composed of highly organized beings. 
“The vertebrate type is represented in the older formations by 
fishes, but the invertebrata are by no means reduced to their less 
complex forms of organization ; since, among the mollusca for example, 
we find numerous gasteropoda and cephalopoda, the most perfect 
orders of the class. . . . . At present, no higher orders of vertebrata 
have been discovered than fishes ; but then all the other groups of 
existing animals (excluding reptiles, birds and mammalia) were repre- 
sented, as perfectly organized as those of the present day. 
“« The intermediate faunas, such as that of the Oolite period, differed 
from those of the earlier and later periods by analogous characters. The 
fishes, the mollusca, the articulata and the radiata, compared with the 
preceding and succeeding forms, exhibit similar organization neither 
more nor less perfect. But these intermediate faunas differed from the 
earlier ones yet further, since the vertebrata in them included reptiles 
and didelphine mammals, while they differed from the more modern 
ones by the absence of the monodelphous mammals. 
“We find that neither the radiata, nor the articulata, nor the mollusca, 
nor the fishes, were imperfectly developed in ancient times, and that 
ever since their first appearance, the species belonging to these classes 
of animals have possessed the same degree of perfection as those that 
live now. It is therefore a mistake to suppose that the early faunas 
generally were composed of animals less perfect than the recent ones, 
although indeed we find that the highest point to which organization 
reached has risen during successive geological periods ; so that while 
fishes at first formed the superior limit of organization, they were 
