238 
POPULAR SCIENCE REVIEW. 
whicli are brought against these various hypotheses affect them 
only, and even if they be valid, leave the general doctrine of 
Evolution untouched. 
On the other hand, it must be admitted that some arguments 
which are adduced against particular forms of the doctrine of 
Evolution, would very seriously affect the whole doctrine if they 
were proof against refutation. For example, there is an objection 
which I see constantly and confidently urged against Mr. Darwin’s 
views, but which really strikes at the heart of the whole doctrine 
of Evolution, so far as it is applied to the organic world. It is 
admitted on all sides that existing animals and plants are marked 
out by natural intervals into sundry very distinct groups: — 
Insects are widely different from Fish — Fish from Keptiles — 
Eeptiles from Mammals — and so on. And out of this fact arises 
the very pertinent objection. How is it, if all animals have pro- 
ceeded by gradual modification from a common stock, that these 
great gaps exist? We, who believe in Evolution, reply, that 
these gaps were once non-existent ; that the connecting forms 
existed in previous epochs of the world’s history, but that they 
have died out. 
Naturally enough then, we are asked to produce these extinct 
onus of life. Among the innumerable fossils of all ages which 
exist, we are asked to point to those which constitute such con- 
necting forms. Our reply to this request is, in most cases, an 
admission that such forms are not forthcoming, and we account 
for this failure of the needful evidence by the known imper- 
fection of the geological record. We say that the series of for- 
mations with which we are acquainted is but a small fraction of 
those which have existed, and that between those which we 
know there are great breaks and gaps. I believe that these 
excuses have very great force ; but I cannot smother the un- 
comfortable feeling that they are excuses. If a landed proprietor 
is asked to produce the title-deeds of his estate, and is obliged 
to reply that some of them were destroyed in a fire a century 
ago, that some were carried off by a dishonest attorney, and that 
the rest are in a safe somewhere, but that he really cannot lay 
his hands upon them ; he cannot, I think, feel pleasantly secure, 
though all his allegations may be correct, and his ownership 
indisputable. But a doctrine is a scientific estate, too often the 
Philosopher’s only estate, and the holder must always be able to 
produce his title-deeds, in the way of direct evidence, or take 
the penalty of that peculiar discomfort to which I have referred. 
You will not be surprised, therefore, if I take this opportunity 
of pointing out that the objection to the doctrine of Evolution, 
drawn from the supposed absence of intermediate forms in the 
fossil state, certainly does not hold good in all cases. In short, 
if I cannot produce the complete title-deeds of the doctrine of 
