dozen (I do not say 100, because we have no such
cases in the animal kingdom) species instead of one. What would really
make these two genera less anomalous would be the creation of many
genera and sub-families round and radiating from them on all sides.
Thus if Australia were destroyed, Didelphys in S. America would be
wonderfully anomalous (this is your case with Proteaceae), whereas now
there are so many genera and little sub-families of Marsupiata that the
group cannot be called aberrant or anomalous. Sagitta (and the earwig)
is one of the most anomalous animals in the world, and not a bit the
less because there are a dozen species. Now, my point (which, I think is
a slightly new point of view) is, if it is extinction which has made the
genus anomalous, as a general rule the same causes of extinction would
allow the existence of only a few species in such genera. Whenever we
meet (which will be on the 23rd [at the] Club) I shall much like to hear
whether this strikes you as sound. I feel all the time on the borders of
a circle of truism. Of course I could not think of such a request,
but you might possibly:--if Bentham does not think the whole subject
rubbish, ask him some time to pick out the dozen most anomalous genera
in the Leguminosae, or any great order of which there is a monograph by
which I could calculate the ordinary percentage of species to genera. I
am the more anxious, as the more I enquire, the fewer are the cases
in which it can be done. It cannot be done in birds, or, I fear, in
mammifers. I doubt much whether in any other class of insects [other
than Curculionidae].

I saw your nice notice of poor Forbes in the "Gardeners' Chronicle,"
and I see in the "Athenaeum" a notice of meeting on last Saturday of his
friends. Of course I shall wish to subscribe as soon as possible to any
memorial...

I have just been testing practically what disuse does in reducing
parts. I have made [skeletons] of wild and tame duck (oh the smell of
well-boiled, high duck!), and I find the tame duck ought, according to
scale of wild prototype, to have its two wings 360 grains in weight; but
it has only 317, or 43 grains too little, or 1/7 of [its] own two wings
too little in weight. This seems rather interesting to me. (43/2. On
the conclusions drawn from these researches, see Mr. Platt Ball, "The
Effects of Use and Disuse" (Nature Series), 1890, page 55. With regard
to his pigeons, Darwin wrote, in November 1855: "I love