P.S. If the result of your measurement of the thickness of the walls turns out at all what I have asserted, would it not be worth while to write a little bit of a paper on the subject of your former note; and "pluck" the bees if they deserve this degradation? Many mathematicians seem to have thought the subject worthy of attention. When the cells are full of honey and hang vertically they have to support a great weight. Can the thicker basal plates be a contrivance to give strength to the whole comb, with less consumption of wax, than if all the sides of the hexagons were thickened?
This crude notion formerly crossed my mind; but of course it is beyond me even to conjecture how the case would be.
A mathematician, Mr. Wright, has been writing on the geometry of bee-cells in the United States in consequence of my book; but I can hardly understand his paper. (75/1. Chauncey Wright, "Remarks on the Architecture of Bees" ("Amer. Acad. Proc." IV., 1857-60, page 432.)
(76/1. The date of this letter is unfortunately doubtful, otherwise it would prove that at an early date he was acquainted with Erasmus Darwin's views on evolution, a fact which has not always been recognised. We can hardly doubt that it was written in 1859, for at this time Mr. Huxley was collecting facts about breeding for his lecture given at the Royal Institution on February 10th, 1860, on "Species and Races and their Origin." See "Life and Letters," II., page 281.)
If on the 11th you have half an hour to spare, you might like to see a very good show of pigeons, and the enclosed card will admit you.
The history of error is quite unimportant, but it is curious to observe how exactly and accurately my grandfather (in "Zoonomia," Volume I., page 504, 1794) gives Lamarck's theory. I will quote one sentence. Speaking of birds' beaks, he says: "All which seem to have been gradually produced during many generations by the perpetual endeavour of the creatures to supply the want of food, and to have been delivered to their posterity with constant improvement of them for the purposes required." Lamarck published "Hist. Zoolog." in 1809. The "Zoonomia" was translated into many languages.
LETTER 77. TO C. LYELL. Down, 28 [June 1859].
It is not worth while troubling you, but my conscience is uneasy at having forgotten to thank you for your "Etna" (77/1. "On the Structure of Lavas which have been consolidated on Steep Slopes, with remarks on the Mode of Origin of Mount Etna, and on the Theory of 'Craters of Elevation'" ("Phil. Trans. R. Soc." Volume CXLVIII., 1858, page 703).), which seems to me a magnificent contribution to volcanic geology, and I should think you might now rest on your oars in this department.
(Editor：meat)