the only good
of separation of sexes. But such wild notions are not worth troubling
you with the reading of.

LETTER 584. TO J.D. HOOKER. Moor Park [May 2nd, 1857].

The most striking case, which I have stumbled on, on apparent, but
false relation of structure of plants to climate, seems to be Meyer
and Doege's remark that there is not one single, even moderately-sized,
family at the Cape of Good Hope which has not one or several species
with heath-like foliage; and when we consider this together with the
number of true heaths, any one would have been justified, had it not
been for our own British heaths (584/1. It is well known that plants
with xerophytic characteristics are not confined to dry climates; it
is only necessary to mention halophytes, alpine plants and certain
epiphytes. The heaths of Northern Europe are placed among the xerophytes
by Warming ("Lehrbuch der okologischen Pflanzengeographie," page 234,
Berlin, 1896).), in saying that heath-like foliage must stand in direct
relation to a dry and moderately warm climate. Does this not strike you
as a good case of false relation? I am so pleased with this place and
the people here, that I am greatly tempted to bring Etty here, for she
has not, on the whole, derived any benefit from Hastings. With thanks
for your never failing assistance to me...

I remember that you were surprised at number of seeds germinating in
pond mud. I tried a fourth pond, and took about as much mud (rather
more than in former case) as would fill a very large breakfast cup, and
before I had left home 118 plants had come up; how many more will be up
on my return I know not. This bears on chance of birds by their muddy
feet transporting fresh-water plants.

This would not be a bad dodge for a collector in country when plants
were not in seed, to collect and dry mud from ponds.

LETTER 585. TO ASA GRAY. Down [1857].

I am very glad to hear that you think of discussing the relative ranges
of the identical and allied U. States and European species, when
you have time. Now this leads me to make a very audacious remark in
opposition to what I imagine Hooker has been writing (585/1. See Letter
338, Volume I.), and to your own scientific conscience. I presume he
has been urging you to finish your great "Flora" before you do anything
else. Now I would say it is your duty to generalise as far as you safely
can from your as yet completed work. Undoubtedly careful discrimination
of specie