My dear Sir

I posted yesterday to M^r Sowerby, some skeleton Plates, showing size of figures, number on Plate &c. Perhaps he will forward these to the Council, with 4 finished drawings, which he has made for me: or if you think fit you can direct him to send them. In either case may I particularly beg you to preserve all carefully & return them to me.— I asked M^r S. to send in his Estimate immediately. Please to remember that if the Council require it I will pledge myself not to exceed 8 Plates, & I think in any case this will suffice.

Allow me to remind you that I have not heard about the colouring: no doubt shells look poor without colour: but for purely scientific ends, if I had one or two Plates coloured it would suffice. Before the Plates are engraved, I must have instructions, for those coloured would have to be engraved rather more lightly.—

With respect to my M.S. for the Lepadidæ, I have some difficulty in answering, partly on account of my Pages containing very unequal quantities (which I have endeavoured to rectify by counting the words in several pages) but chiefly from your not having told me in what type the Council would wish the Book to appear in. Hence I must trouble you with two or three Estimates.—

If my M.S. were printed in the type used in D^r. Baird’s Entomostraca,¹ (containing 360 words in Page) it would run out, as nearly as I can possibly estimate, to 192 pages; this, size, however, strikes me as quite useless in a series of descriptions. I think the work would look quite well enough, if the specific characters were printed in this larger type, & the detailed descriptions in the small type (530 words in Page) used in the “Reports of Zoology & Bot. for 1841 & 1842”;—in this case I believe my M.S. would go in 150 pages.— Or lastly if a uniform type was decided on, the larger of the two (400 in Page) used in the above Report appears to me very good, & then the number of my Pages would be 175.—²

I fear my second Systematic Part will be fully twice the size of this & certainly ought to have more than twice the number of Plates.³ I do hope that the Council, if they do not publish one Part in 1851, will publish all in 1852.; otherwise my monograph will be so greatly delayed.⁴

Pray believe me, my dear Sir | Your’s sincerely | C. Darwin