Dec. 15, 1881] 
NATUCORE 
147 
that we are called upon to say in each case, ‘ Which is 
now most probable, my ignorance of all possible effects 
of existing causes,’ or that ‘ the beginning’ is the cause of 
this puzzling phenomenon?” ‘‘It is not the beginning I 
look for but proofs of a frogressive state of existence in 
the globe, the probability of which is Aroved by the 
analogy of changes in organic life’’ (vol. i. p. 270). See 
also upon the same subject his letter to Whewell in 1837 
_ (vol. ii. p. 2). 
The other question upon which Lyell’s reasonings in 
his “ Principles’? betrayed weakness and inconsistency 
was that of the cause of the appearance from time to time 
of new species of plants and animals upon the earth. 
While stoutly maintaining the sufficiency of existing 
causes to account for the gradual disappearance of 
species by extinction, he felt himself compelled to invoke 
a creative power to introduce the new species as they 
were required. But, before we blame Lyell for this appa- 
rent weakness, we ought to remember that the work of 
Lamarck, the only serious attempt which had been at 
that time made to account for the origin of species, 
though brilliant and suggestive, was full of assumptions 
and fallacies that could not fail to betray themselves to 
Lyell’s logical mind, and to militate against his acceptance 
of the theory. Lyell, moreover, saw only too clearly that 
the origin of man could not be treated of on different 
principles to that of other species of animals, and to have 
come into conflict with the prejudices of the day upon 
such a point as this, would have been to sacrifice all 
chance of a patient hearing for his arguments in favour 
of the “good cause’’ of which he felt himself to be the 
apostle. A very interesting letter written by him to Sir 
John Herschel in 1836, shows very clearly that Lyell had 
even at that early date thought deeply on the question of 
the origin of species by natural causes. 
“Tn regard to the origination of new species, I am very 
glad to find that you think it probable that it may be 
carried on through the intervention of intermediate 
causes. I left this rather to be inferred, not thinking it 
worth while to offend a certain class of persons by em- 
bodying in words what would only be a speculation. But 
the German critics have attacked me vigorously, saying 
that by the impugning of the doctrine of spontaneous 
generation, and substituting nothing in its place, I have 
left them nothing but the direct and miraculous interven- 
tion of the First Cause, as often as a new species is intro- 
duced and hence I have overthrown my own doctrine of 
revolutions, carried on by a regular system of secondary 
causes. I have not wasted time in any controversies 
with them or others, except so far as modifying in new 
editions some opinions or expressions, and fortifying 
others, and by this means I have spared a great deal of 
ink-shed, and have upon the whole been very fairly treated 
by the critics. When I first came to the notion, which I 
never saw expressed elsewhere, though I have no doubt it 
had all been thought out before, of a succession of ex- 
tinction of species, and creation of new ones, going on 
perpetually now, and through an indefinite period of the 
past, and to continue for ages to come, all in accommo- 
dation to the changes which must continue in the inani- 
mate and habitable earth, the idea struck me as the 
grandest which I had ever conceived, so far as regards 
the attributes of the Presiding Mind. For one can in 
imagination summon before us a small part at least of 
the circumstances that must be contemplated and fore- 
known, before it can be decided what powers and quali- 
ties a new species must have in order to enable it to 
endure for a given time, and to play its part in due rela- 
tion to all other beings destined to coexist with it, before 
it dies out. It might be necessary, perhaps, to be able 
to know the number by which each species would be 
represented in a given region 10,000 years hence, as much 
as for Babbage to find what would be the place of every 
wheel in his new calculating machine at each movement. 
“Tt may be seen that unless some slight additional 
precaution be taken, the species about to be born would 
at a certain era be reduced to too low a number. There 
may be a thousand modes of insuring its duration beyond 
that time ; one, for example, may be the rendering it 
more prolific, but this would perhaps make it press too 
hard upon other species at other times. Now it it be an 
insect it may be made in some of its transformations to 
resemble a dead stick, or a leaf, or a lichen, or a stone, 
so as to be somewhat less easily found by its enemies ; 
or if this would make it too strong, an occasional variety 
of the species may have this advantage conferred upon 
it; or if this would be still too much, one sex of a certain 
variety. Probably there is scarcely a dash of colour on 
the wing.or body of which the choice would be quite 
arbitrary, or which might not affect its duration for 
thousands of years. I have been told that the leaf-like 
expansion of the abdomen and thighs of a certain Bra- 
zilian Mantis turn from green to yellow as autumn ad- 
vances, together with the leaves of the plants among 
which it seeks for its prey. Now if species come in in 
succession, such contrivances must sometimes be made, 
and such relations predetermined between species, as the 
Mantis, for example, and plants not then existing, but 
which it was foreseen would exist together with some 
particular climate at a given time. But I cannot do justice 
to this train of speculation in a letter, and will only say 
that it seems to me to offer a more beautiful subject for 
reasoning and reflecting on, than the notion of great 
batches of new species all coming in, and afterwards 
going out at once” (vol. i. pp. 467, 469). 
It is probable that during later years Lyell receded 
somewhat from the position he was prepared to take up 
at the time when he wrote the above. The crudeness of 
speculation and ignorance of scientific facts which charac- 
terised the earlier editions of the “‘ Vestiges of Creation ” 
had in all likelihood not a little to do with this revulsion 
of thought, while the powerful influence of the leaders of 
biological thought, Edward [Forbes and Louis Agassiz, 
always exercised in support of the idea of the permanency 
of species, doubtless had no little weight with Lyell, as it 
had with nearly all his contemporaries. How readily 
Lyell welcomed and embraced the views of Darwin as 
soon as they were published we all know, for he could not 
fail to see that by incorporation of the theory of natural 
selection into his work he was for the first time able to 
make it complete and consistent with itself. It is inte- 
resting to read in the volume before us the impressions 
made upon him by the first reading of the “ Origin of 
Species’’ in 1859. 
“My dear Darwin,—I have just finished your volume, 
and right glad I am that I did my best with Hooker to 
persuade you to publish it without waiting for a time, 
which probably could never have arrived, though you 
lived to the age of a hundred, when you had prepared 
all your facts on which you ground so many grand 
generalisations. 
“Tt is a splendid case of close reasoning and long- 
sustained argument throughout so many pages, the con- 
densation immense, too great perhaps for the uninitiated, 
but an effective and important preliminary statement, 
which will admit, even before your detailed proofs 
appear, of some occasional useful exemplifications, such 
as your pigeons and cirripedes, of which you make such 
excellent use. 
