Volume I Part 16 (1/2)

I stated the facts merely to give the general reader an idea of the thickness of the walls. (73/1. The walls of bees' cells: see Letter 173.)

Especially if I had seen that the fact had any general bearing, I should have stated that as far as I could measure, the walls are by no means perfectly of the same thickness. Also I should have stated that the chief difference is when the thickness of walls of the upper part of the hexagon and of the pyramidal basal plates are contrasted. Will you oblige me by looking with a strong lens at the bit of comb, brus.h.i.+ng off with a knife the upper thickened edges, and then compare, by eye alone, the thickness of the walls there with the thickness of the basal plates, as seen in any cross section. I should very much like to hear whether, even in this way, the difference is not perceptible. It is generally thus perceptible by comparing the thickness of the walls of the hexagon (if 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 Inst.i.tute 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, I think my discussion nearly removes a very great difficulty. I believe in its truth chiefly from the existence of the Melipona, which makes a comb so intermediate in structure between that of the humble and hive-bee, and especially from the new and curious fact of the bees making smooth cups or saucers when they excavated in a thick piece of wax, which saucers stood so close that hexagons were built on their intersecting edges. And, lastly, because when they excavated on a thin slip of wax, the excavation on both sides of similar smooth basins was stopped, and flat planes left between the nearly opposed basins. If my view were wholly false these cases would, I think, never have occurred. Sedgwick and Co. may abuse me to their hearts' content, but I shall as yet continue to think that mine is a rational explanation (as far as it goes) of their method of work.

LETTER 75. TO W.H. MILLER.

Down, December 1st [1859].

Some months ago you were so kind as to say you would measure the thickness of the walls of the basal and side plates of the cell of the bee. Could you find time to do so soon? Why I want it soon, is that I have lately heard from Murray that he sold at his sale far more copies than he has of the ”Origin of Species,” and that I must immediately prepare a new edition, which I am now correcting. By the way, I hear from Murray that all the attacks heaped on my book do not seem to have at all injured the sale, which will make poor dear old Sedgwick groan.

If the basal plates and walls do differ considerably in thickness, as they certainly did in the one or two cells which I measured without particular care (as I never thought the point of any importance), will you tell me the bearing of the fact as simply as you can, for the chance of one so stupid as I am in geometry being able to understand?

Would the greater thickness of the basal plates and of the rim of the hexagons be a good adaptation to carry the vertical weight of the cells filled with honey and supporting cl.u.s.ters of living bees?

Will you endeavour to screw out time and grant me this favour?

P.S. If the result of your measurement of the thickness of the walls turns out at all what I have a.s.serted, 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.)

LETTER 76. TO T.H. HUXLEY.

(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 Inst.i.tution on February 10th, 1860, on ”Species and Races and their Origin.” See ”Life and Letters,” II., page 281.)

Down [June?] 9 [1859?].

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].