lds. There has been too much change
in comparison with the little change of isolated alpine forms; but you
will see this in my book. (347/2. "Origin of Species" (1859), Chapter
XI., pages 365 et seq.) I may just make a few remarks why at first sight
I do not attach much weight to the argument in your letter about the
warmer climate. Firstly, about the level of the land having been lower
subsequently to Glacial period, as evidenced by the whole, etc., I
doubt whether meteorological knowledge is sufficient for this deduction:
turning to the S. hemisphere, it might be argued that a greater extent
of water made the temperature lower; and when much of the northern land
was lower, it would have been covered by the sea and intermigration
between Old and New Worlds would have been checked. Secondly, I doubt
whether any inference on nature of climate can be deduced from extinct
species of mammals. If the musk-ox and deer of great size of your
Barren-Grounds had been known only by fossil bones, who would have
ventured to surmise the excessively cold climate they lived under? With
respect to food of large animals, if you care about the subject will you
turn to my discussion on this subject partly in respect to the Elephas
primigenius in my "Journal of Researches" (Murray's Home and Colonial
Library), Chapter V., page 85. (347/3. "The firm conviction of the
necessity of a vegetation possessing a character of tropical luxuriance
to support such large animals, and the impossibility of reconciling this
with the proximity of perpetual congelation, was one chief cause of
the several theories of sudden revolutions of climate...I am far from
supposing that the climate has not changed since the period when these
animals lived, which now lie buried in the ice. At present I only wish
to show that as far as quantity of food alone is concerned, the ancient
rhinoceroses might have roamed over the steppes of Central Siberia
even in their present condition, as well as the living rhinoceroses and
elephants over the karoos of Southern Africa" ("Journal of Researches,"
page 89, 1888).) In this country we infer from remains of Elephas
primigenius that the climate at the period of its embedment was very
severe, as seems countenanced by its woolly covering, by the nature
of the deposits with angular fragments, the nature of the co-embedded
shells, and co-existence of the musk-ox. I had formerly gathered from
Lyell that the relative position of the Megath