My dear Sir

I am extremely much obliged to you for your interesting note. Now that you are enjoying holidays,¹ it is really a shame to ask you to write again, but if you w^d. send me literally a single line, just to say which of the two Leuckart’s, whether “Fr. Sig.”² who has been publishing much since 1820, or Rud. Leuckart,³ who published in 1847 on Sepiola, & in 1851 on Polymorphismus.⁴

I enclose my list & I have still one more copy, which I will either keep for somebody turning without you think fit to add another name.—

I have sent my Book for you to Jermyn St, & M^r. Baily says he has sent it on to D^r. Lankester according to your instructions.—

I am much pleased to hear what you say about the Branchiæ of Balanus: it is exactly my view, the ovigerous fræna having been metamorphosed to this new function, & the glands having become aborted.— And the case strikes me as rather pretty.⁵

If ever so practised a hand as you sets to work on the Cirripedia I have no doubt whatever, you will discover many errors on my part: I learnt the art of minute dissection in this work, which for a long time was the work of a mere beginner.—⁶

I most heartily agree with you, in what you say about Owen & the pursuit of Science.—⁷

Very sincerely yours | C. Darwin

I cannot find out in any Bibliographia, where Leydig⁸ has published, though I know the name.— Will it not be rash to send on chance to Würzburg Krohn⁹ I think I c^d. send to care of Müller as he often publishes in the Archif.¹⁰

I will follow your advice & send through Williams & Norgate¹¹