My dear Sir

I am much obliged by your note. I will confine myself to the 8 Plates, of which two only shall be coloured.—¹ It seems that I have misexpressed myself to make you suppose that M^r Sowerby had made for me any “engraved Plates”; what he has made are some drawings, which would give you a correct idea of the engravings when made.—

I shall be much obliged for the skeleton Plates, & the drawings (if you have these) to be returned to me as soon as convenient to yourself.—

I sh^d. be particularly obliged if you would inform me, at what period of 1851, my Part will appear;² pray do not suppose that I shall cause delay, but I want to know as I think it will be more convenient to me not to set to work at the 8 Plates, till I have got through the press the fossil Part, which the Palæontographical Soc. is going to publish. If you will tell me exactly what you wish, I sh^d be obliged; & allow me to assure you that I am not dilatory, though my health allows me to work but for a very short time daily.

Your’s sincerely, | C. Darwin.