ence lies before me of the existence of a new Labyrinthodont
(_Pholidogaster_), from the Edinburgh coal-field, with well-ossified
vertebral centra.

XI.

GEOLOGICAL REFORM.

"A great reform in geological speculation seems now to have become
necessary."

"It is quite certain that a great mistake has been made,--that
British popular geology at the present time is in direct opposition
to the principles of Natural Philosophy."[39]

In reviewing the course of geological thought during the past year, for
the purpose of discovering those matters to which I might most fitly
direct your attention in the Address which it now becomes my duty to
deliver from the Presidential Chair, the two somewhat alarming sentences
which I have just read, and which occur in an able and interesting essay
by an eminent natural philosopher, rose into such prominence before my
mind that they eclipsed everything else.

It surely is a matter of paramount importance for the British geologists
(some of them very popular geologists too) here in solemn annual session
assembled, to inquire whether the severe judgment thus passed upon them,
by so high an authority as Sir William Thomson is one to which they
must plead guilty _sans phrase_, or whether they are prepared to say
"not guilty," and appeal for a reversal of the sentence to that higher
court of educated scientific opinion to which we are all amenable.

As your attorney-general for the time being, I thought I could not do
better than get up the case with a view of advising you. It is true that
the charges brought forward by the other side involve the consideration
of matters quite foreign to the pursuits with which I am ordinarily
occupied; but, in that respect, I am only in the position which is, nine
times out of ten, occupied by counsel, who nevertheless contrive to gain
their causes, mainly by force of mother-wit and common sense, aided by
some training in other intellectual exercises.

Nerved by such precedents, I proceed to put my pleading before you.

And the first question with which I propose to deal is, What is it to
which Sir W. Thomson refers when he speaks of "geological speculation"
and "British popular geology"?

I find three, more or less contradictory, systems of geological thought,
each of which might fairly enough claim these appellations, standing
side by side in Britain. I shall call one of them CATASTROPHISM, another
UNIFORMITARIANISM