... Conundrum? Why does the Dionæa trap close only part way, so as to cross the bristles of edge only, at first, and afterwards close fully?

Darwin has hit it. I wonder you or I never thought of it.

A. G.

TO A. DE CANDOLLE.

Cambridge, October 27, 1873.

My dear De Candolle,—If I were a better correspondent, I should have long ago thanked you for your interesting and welcome letter of August 11, from Samaden. I was in the Engadine when last in Switzerland, and got near the top of Piz Langarde, when a storm drove me back.

Your announcement leads me to expect soon the new (and alas, last!) volume of the “Prodromus.” Well, it must give you a huge sense of relief to have it off your hands; something like the relief I now feel at the termination, at the close of thirty-one years, of my professorial duties, upon which you felicitate me. On account of a summer course of instruction, which I felt bound to initiate for my successor, I did not really close my labors until the end of July. Since then I have been able to work at systematic botany very steadily. We took, my wife and I, a holiday of a fortnight, in which we visited friends on the Hudson River and its tributaries, at the close of September, just as the foliage was beginning to display the bright autumnal tints, which this year have been unusually gorgeous, and have not yet disappeared, although the leaves are now falling fast. The sight is most enjoyable to me in the earlier autumn, when the verdure still prevails and makes a setting for the red, yellow, and russet.

I am now deep in the Compositæ for the “California Flora” of my friend Brewer, and so am trying Bentham’s work. It generally holds good,—wonderfully so, considering its extent, and the comparatively short time he took for it.

Your agreeable volume of “Miscellanies” is now in the hands of your old friend and my neighbor, Jules Marcou; who asked to borrow it, having been unable to purchase a copy. It is reported out of print. I think I sent you a light article I wrote for the “Nation” last summer,—I believe in June,—in which I gave an abstract of your essay on the Dominant Language of the Twentieth Century. It has attracted considerable attention. I see that those who have studied the subject think that the increase of population in North America is not to go on at the rate it has been going; that the check is already apparent.

A week or two ago appeared in the “Nation” an article (sent to you last week by post), in which I had occasion to notice some other parts of your volume, at considerable length. I have also been tempted to give some account of your essay on Natural Selection as applied to man; but I find it would take me too much out of my own line, and absorb time which I cannot spare. Indeed, I have only looked over that essay, and am not qualified to abstract, still less to criticise it. The longest article of the volume, which gives the title, I have not given as much attention to as I ought, probably, or I should perhaps value it more highly. But it seems to me that membership in scientific academies—the three you take not excepted—is so largely affected by circumstance, irrespective of talent and of the value of work done, that one cannot very confidently base general conclusions upon the data. Yet I have no great confidence in my opinion. Anyway, the article is full of interesting matters....