vee 
Miscellaneous. 377 
that numerous Tertiary species have continued down into the qua- 
ternary, and many of them to the present time. A goodly per- 
centage of the earlier and nearly half of the later Tertiary Mol- 
lusca, according to Deshayes, Lyell, and, if we mistake not, Bronn, 
still live. This identification, however, is now questioned by a 
naturalist of the very highest authority. But, in its bearings on 
the new theory, the point here turns not upon absolute identity so 
much as upon close resemblance. For those who, with Agassiz, 
doubt the specific identity in any of these cases, and those who 
say, with Pictet, that “the later Tertiary deposits contain in ge- 
neral the débris of species very nearly related to those which still 
exist, belonging to the same genera, but specifically different,” may 
also agree with Pictet that the nearly related species of successive 
faunas must or may have had “a material connexion.” Now the 
only material connexion that we have an idea of in such a case is a 
genealogical one. And the supposition of a genealogical connexion 
is surely not unnatural in such cases—is demonstrably the natural 
one as respects all those Tertiary species which experienced natu- 
ralists have pronounced to be identical with existing ones, but which 
others now deem distinct ; for to identify the two is the same thing 
as to conclude the one to be ancestors of the other. No doubt there 
are differences between the Tertiary and the present individuals— 
differences equally noted by both classes of naturalists, but differently 
estimated. By the one these are deemed quite compatible, by 
the other incompatible with community of origin. But who can 
tell us what amount of difference is compatible with community of 
origin? This is the very question at issue, and one to be settled by 
observation alone. Who would have thought that the peach and the 
nectarine came from one stock? But this being proved, is it now 
very improbable that both were derived from the almond, or from 
some common amygdaline progenitor? Who would have thought 
that the cabbage, cauliflower, broccoli, kale, and kohlrabi are deriva- 
tives of one species, and rape or colza, turnip, and probably rutabaga, 
of another species? And who that is convinced of this can long 
undoubtingly hold the original distinctness of turnips from cabbages 
as an article of faith? On scientific grounds, may not a primordial 
cabbage or rape be assumed as the ancestor of all the cabbage races, 
on much the same ground that we assume a common ancestry for 
the diversified human races? If all our breeds of cattle came from 
one stock, why not this stock from the Aurochs, which has had all the 
time between the diluvial and the historic periods in which to set off 
a variation perhaps no greater than the difference between some sorts 
of cattle? 
That considerable differences are often discernible between Tertiary 
individuals and their supposed descendants of the present day affords 
no argument against Darwin’s theory, as has been rashly thought, 
but is decidedly in its favour. If the identification were so. perfect 
that no more differences were observable between the Tertiary and 
the recent shells than between various individuals of either, then 
Darwin’s opponents, who argue the immutability of species from the 
Ann. & Mag. N. Hist. Ser. 3. Vol. vi. 
