My dear Sir,

I have great pleasure in lending you D^r Staudinger’s catalogue of Europæan Lepidoptera— You will see that I have marked a few species with a + of which the males are priced higher than the females but the latter sex is apterous and some of them like mere maggots and I expect few collectors care about more than one specimen as they are certainly not ornamental in a cabinet— I do not think there are a dozen other species of which the males are priced higher than the females—¹ I do not think there would be any fallacy to this test—(money value) as it clearly shows that females are more difficult to procure than the males and although in a few cases this may arise from the different habits of the two sexes yet this cannot be said of the butterflies and I think there is not an instance among them of the male being priced higher than the female—² You can keep the Catalogue as long as you please—

Last evening I heard an Anobium ticking and found it— I will send it to you— if you place the pill box on a table I daresay you will hear it ticking in the evening and if the lid is carefully taken off and you imitate its ticking I have no doubt you will soon find that it will answer you—³

With best wishes believe me | My dear Sir | Yours very Sincerely | Henry Doubleday

C Darwin Esq