compared with the New World. 265 
more considerable proportions than anywhere else; it was, in fact, 
the twentieth part of the flora of this country. This relation con- 
tinues nearly the same when we compare the flora of well deter- 
mined formations, as, for example, that of the coal and transition for- 
mations. It comprehends 500 species, while Europe possesses nearly 
12,000 living plants. Even though the flora of the ancient world 
should be the twentieth part of that which now adorns the earth, it 
would have been much inferior to the existing vegetation in regard 
to the variety of its species. The flora of amber, compared with that 
of Germany, although it occupied a much more considerable extent,» 
yet gives us a smaller figure than the whole of the two vegetations, 
- According to the last edition of Kocks (1851,, the flora of Ger- 
many comprehends 6802 cryptogamous, 8454 phanerogamous species, 
amounting together to 10,256 species. The number of vegetables 
hitherto observed in the various amber deposits does not exceed 162. 
This flora was, therefore, 63 times less considerable than the former, 
In truth, all the vegetables of the ancient world have not reached 
our times, and we are far from being acquainted with the whole of 
the fossil species; but making a large allowance for these circum- 
stances, and reducing the relative number given by observation to a 
fortieth part, one of these floras would be still much more varied 
than the other. The same facts ought to appear among animals, 
since even those supported by flesh and living prey feed on herbi- 
vorous species. Two examples will be sufficient to prove the small 
number of the ancient animal races, compared with those living at 
the present time. We shall take them from the classes best known ; 
for example, the fishes. Eighteen hundred species appear to have 
existed in the old world, while about 9000 have been enumerated 
belonging to our own epoch, a relation which is::1: 5. This rela- 
tion, superior to that presented by vegetables, is probably owing to 
this, that the study of fossil fishes is perhaps more advanced that 
that of the living species. It is entirely different with the insects 
of the ancient world; not more, at least, have been observed up to 
the present time than about 1000 species, while the number of living 
races already amounts to 80,000. However considerable this num- 
ber may appear, it is still short of that which calculations, seemingly 
well founded, attribute to the species of our world. The latter is 
no less than 362,000, of which 282,000 remain to be discovered. 
Entomologists have, therefore, much to do in order to fill up this 
blank. | 
Nore 19. It is only in recent sedimentary deposits that we find 
species like those now living. This identity between a small num- 
ber of the species of geological times and our own, admitted by 
English and Italian geologists, is however denied by some French 
naturalists. In order to determine on which side the truth lies, 
we have undertaken a work with the intention of definitely settling 
this question. This work is sufficiently advanced to enable us cer- , 
