training, it should be possible to give a new and healthier direction
to all biological science. Meanwhile, opportunities must be seized at
the risk of a reputation for desultoriness.

But the irony of circumstances diverted much of his energy into yet
more diverse fields. When Sir Henry de la Beche first offered him the
posts of Palæontologist and Lecturer on Natural History vacated by
Professor Forbes, he says:--

I refused the former point blank, and accepted the latter
only provisionally, telling Sir Henry that I did not care for
fossils, and that I should give up Natural History as soon as
I could get a physiological post. But I held the office
for thirty-one years, and a large part of my work has been
palæontological.

Palæontology was his business, and he became a Master in it also,
with the result that he forged himself a mighty weapon for use in the
struggle over the Origin of Species.

In one of his later Essays he compares the study of human physiology
to the Atlantic Ocean:--

Like the Atlantic between the Old and the New Worlds, its
waves wash the shores of the two worlds of matter and of mind;
its tributary streams flow from both; through its waters, as
yet unfurrowed by the keel of any Columbus, lies the road, if
such there be, from the one to the other; far away from that
North-West Passage of mere speculation in which so many brave
souls have been helplessly frozen up.