not taken very close to the angle) near to the basal plates, where
the comparison by eye is of course easier. Your letter actually turned
me sick with panic; from not seeing any great importance [in the]
fact, till I looked at my notes, I did not remember that I made several
measurements. I have now repeated the same measurements, roughly with
the same general results, but the difference, I think, is hardly double.

I should not have mentioned the thickness of the basal plates at all,
had I not thought it would give an unfair notion of the thickness of the
walls to state the lesser measurements alone.

LETTER 74. TO W.H. MILLER. [1859]

I had no thought that you would measure the thickness of the walls of
the cells; but if you will, and allow me to give your measurements,
it will be an immense advantage. As it is no trouble, I send more
specimens. If you measure, please observe that I measured the thickness
of the walls of the hexagonal prisms not very near the base; but from
your very interesting remarks the lower part of the walls ought to be
measured.

Thank you for the suggestion about how bees judge of angles and
distances. I will keep it in mind. It is a complete perplexity to me,
and yet certainly insects can rudely somehow judge of distance. There
are special difficulties on account of the gradation in size between the
worker-scells and the larger drone-cells. I am trying to test the case
practically by getting combs of different species, and of our own bee
from different climates. I have lately had some from the W. Indies of
our common bee, but the cells SEEM certainly to be larger; but they have
not yet been carefully measured. I will keep your suggestion in mind
whenever I return to experiments on living bees; but that will not be
soon.

As you have been considering my little discussion in relation to Lord
Brougham (74/1. Lord Brougham's paper on "The Mathematical Structure
of Bees' Cells," read before the National Institute of France in May,
1858.), and as I have been more vituperated for this part than for
almost any other, I should like just to tell you how I think the case
stands. The discussion viewed by itself is worth little more than the
paper on which it is printed, except in so far as it contains three or
four certainly new facts. But to those who are inclined to believe the
general truth of the conclusion that species and their instincts are
slowly modified by what I call Natural Selection,