To W. R. Grove 4 July 1
Down, | Beckenham, Kent.
I never before noticed with any care the curious marks on our finger-ends.—2 I presume they vary, as my first finger differs somewhat from yours.—3 I apprehend the cause must be the same which leads to the hair, & more especially the fœtal lanugo, being arranged in wonderfully many & complex, whirl-pool sort of lines or spires on different parts of the body.— They are very complex on the upper lip.— Eschricht who has studied the subject, of the lanugo, & to whose work I allude in my Descent of Man, is inclined to attribute their positions & centres to the last points closed in, or over which the skin is finally developed, in the growing embryo.—4 But he speaks rather doubtfully on this head.— If the lines could be traced & coloured all over the body, what a splendidly tattooed animal, man would turn out.—
Yours very sincerely | Ch. Darwin
Has never before noticed with care the markings on finger-ends. Compares them to the complex whirl-pool patterns of human foetal lanugo.