My dear M^r. Salvin

I am going to beg a favour of you,—that is if you can grant it easily.— I believe that you have studied the Duck-family, & I want to know something about the gradation of character in the lamellæ of their beaks, just to illustrate another point.¹ In the Shoveller I find that the lamellæ are very prominent & fine, & in the Australian Malacorhynchus even finer; but I have not as yet carefully cleaned & compared the beaks of my specimens.—² In the common Duck they are far less developed & prominent;³ & in the common Goose even less so, & seem to serve more as teeth, rather than as a sifting apparatus.—⁴ Now can you tell me whether the lamellæ are less developed in any true Duck than in the common Duck? As it would be fairer to end the series with a Duck rather than with a Goose.— I sh^d., however, much like to know whether the lamellæ are less developed or prominent in any other species of goose than in the common kind.—

Are the lamellæ more prominent & finer in any Duck than in the Shoveller & Malacorhynchus? Pray do not for one moment suppose that I am so unreasonable as to ask you to compare many species for me; but I have thought that your memory might guide you to one or two species, & then a glance would answer my query.

Pray forgive me for troubling you & believe me | Yours very sincerely | Ch. Darwin