TRANSACTIONS OF SECTION D. uy 
the question as to what lies beneath. Long before the ‘Challenger’ had proved 
the persistence of oceanic and continental areas, Darwin, with extraordinary fore- 
sight, and opposed by all other naturalists and geologists, including his revered 
teacher, Lyell, had come to the same conclusion. His reasoning on the subject is 
so convincing that it is remarkable that he made so few converts, and this is all 
the more surprising since the arguments were published in the ‘ Origin of Species, 
which in other respects produced so profound an effect. In speculating as to the 
rocks in which the remains of the ancestors of the earliest known fossils may still 
exist, he suggested that, although the existing relationship between the positions 
of our present oceans and continental areas is of immense antiquity, there is no 
reason for the belief that it has persisted for an indefinite period, but that at some 
time long antecedent to the earliest known fossiliferous rocks ‘continents may 
have existed where oceans are now spread out; and clear and open oceans may 
have existed where our continents now stand.’ Not the least interesting result 
would be the test of this hypothesis, which would probably be forthcoming as the 
result of boring into the floor of a deep ocean; for although, as Darwin pointed 
out, it is likely enough that such rocks would be highly metamorphosed, yet it 
might still be possible to ascertain whether they had at any time formed part of a 
continental deposit, and perhaps to discover much more than this. Such an under- 
taking might be carried out in conjunction with other investigations of the highest 
interest, such as the attempt to obtain a record of the swing of a pendulum at the 
bottom of the ocean. 
We now come to the strictly biological part of our subject—to the inquiry as 
to how much of the whole scheme of organic evolution has been worked out in 
the time during which the fossiliferous rocks were formed, and how far, therefore, 
the time required by the geologist is sufficient. 
It is first necessary to consider Lord Kelvin’s suggestion that life may have 
reached the earth on a meteorite—a suggestion which might be made the basis 
of an attempt to rescue us from the dilemma in which we were placed by the 
insufficiency of time for evolution. It might be argued that the evolution which 
took place elsewhere may have been merely completed, in a comparatively brief 
space of time, on our earth. 
We Imow nothing of the origin of life here or elsewhere, and our only 
attitude towards this or any other hypothesis on the subject is that of the 
anxious inquirer for some particle of evidence. But a few brief considerations 
will show%that no escape from the demands for time can be gained in this way. 
_ Our argument does not deal with the time required for the origin of life, or 
for the development of the lowest beings with which we are acquainted from the 
first formed beings, of which we know nothing. Both these processes may have 
required an immensity of time ; but as we know nothing whatever about them, aad 
have as yet no prospect of acquiring any information, we are compelled to confine 
ourselves to as much of the process of evolution as we can infer from the structure 
of living and fossil forms—that is, as regards animals, to the development of the 
‘simplest into the most complex Protozoa, the evolution of the Metazoa from the 
Protozoa, and the branching of the former into its numerous Phyla, with all their 
Classes, Orders, Families, Genera, and Species. But we shall find that this is 
“quite enough to necessitate a very large increase in the time estimated by the 
geologist. 
The Protozoa, simple and complex, still exist upon the earth in countless 
“species, together with the Metazoan Phyla. Descendants of forms which in their 
day constituted the beginning of that scheme of evolution which | have defined 
above, descendants, furthermore, of a large proportion of those forms which, age 
after age, constituted the shifting phases of its onward progress, still exist, and in 
a sufficiently unmodified condition to enable us to reconstruct, at any rate in 
mere outline, the history of the past. Innumerable details and many phases of 
supreme importance are ‘still hidden from us, some of them perhaps never to be 
recovered. But this frank admission, and the eager and premature attempts to 
expound too much, to go further than the evidence permits, must not be allowed 
