with you that the difference would be too great to account for by the
recent Glacial period. I agree, also, with you in utterly rejecting an
independent origin for these Carabi. There is a difficulty, as far as I
know, in our ignorance whether insects change quickly in time; you could
judge of this by knowing how far closely allied coleoptera generally have
much restricted ranges, for this almost implies rapid change. What a
curious case is offered by land-shells, which become modified in every sub-
district, and have yet retained the same general structure from very remote
geological periods! When working at the Glacial period, I remember feeling
much surprised how few birds, no mammals, and very few sea-mollusca seemed
to have crossed, or deeply entered, the inter-tropical regions during the
cold period. Insects, from all you say, seem to come under the same
category. Plants seem to migrate more readily than animals. Do not
underrate the length of Glacial period: Forbes used to argue that it was
equivalent to the whole of the Pleistocene period in the warmer latitudes.
I believe, with you, that we shall be driven to an older Glacial period.

I am very sorry to hear about the British Museum; it would be hopeless to
contend against any one supported by Owen. Perhaps another chance might
occur before very long. How would it be to speak to Owen as soon as your
own mind is made up? From what I have heard, since talking to you, I fear
the strongest personal interest with a Minister is requisite for a pension.

Farewell, and may success attend the acerrimo pro-pugnatori.

P.S. I deeply wish you could find some situation in which you could give
your time to science; it would be a great thing for science and for
yourself.