otal revilers,"--so the revilers are tearing each other
to pieces. I suppose Sedgwick will be very fierce against me at the
Philosophical Society. (100/3. The meeting of the "Cambridge Phil.
Soc." was held on May 7th, 1860, and fully reported in the "Cambridge
Chronicle," May 19th. Sedgwick is reported to have said that "Darwin's
theory is not inductive--is not based on a series of acknowledged
facts, leading to a general conclusion evolved, logically out of the
facts...The only facts he pretends to adduce, as true elements of
proof, are the varieties produced by domestication and the artifices
of crossbreeding." Sedgwick went on to speak of the vexatious
multiplication of supposed species, and adds, "In this respect Darwin's
theory may help to simplify our classifications, and thereby do good
service to modern science. But he has not undermined any grand truth
in the constancy of natural laws, and the continuity of true species.")
Judging from his notice in the "Spectator," (100/4. March 24th, 1860;
see "Life and Letters," II., page 297.) he will misrepresent me, but it
will certainly be unintentionally done. In a letter to me, and in
the above notice, he talks much about my departing from the spirit of
inductive philosophy. I wish, if you ever talk on the subject to him,
you would ask him whether it was not allowable (and a great step) to
invent the undulatory theory of light, i.e. hypothetical undulations,
in a hypothetical substance, the ether. And if this be so, why may I not
invent the hypothesis of Natural Selection (which from the analogy
of domestic productions, and from what we know of the struggle for
existence and of the variability of organic beings, is, in some very
slight degree, in itself probable) and try whether this hypothesis of
Natural Selection does not explain (as I think it does) a large
number of facts in geographical distribution--geological succession,
classification, morphology, embryology, etc. I should really much like
to know why such an hypothesis as the undulation of the ether may be
invented, and why I may not invent (not that I did invent it, for I
was led to it by studying domestic varieties) any hypothesis, such as
Natural Selection.

Pray forgive me and my pen for running away with me, and scribbling on
at such length.

I can perfectly understand Sedgwick (100/5. See "Life and Letters," II.,
page 247; the letter is there dated December 24th, but must, we think,
have been written i