To William Turner 15 January 1
Down. | Bromley. | Kent. S.E.
My dear Sir
As you were so kind as to say that I might ask you a few more questions, & as my wishes are now rather more definite, I do so now;1 but you must not suppose that I am in any hurry for an answer.
(1) One or two good cases of any rudiment of a muscle, would suffice (I have lost one good case which I copied from some French writer): if any muscle in our arms exists in a rudimentary or nearly rudimentary condition, & which would be of service to a quadruped, going on all fours; such case would perhaps be best.2
(2) You reminded me that there were two sets of muscles for moving the whole ear & its parts; which of such muscles are rudimentary in human ear?3
(3) I have used your information (from Theile etc) about muscles to Os Coccyx:4 if my memory does not deceive me, those 4 coccygeal bones contain spinal marrow at an early embryonic age, & afterwards it retreats. If this is so, are vestiges of membranes of spinal marrow retained?5
(4) I have given case of Prostate gland (to which you allude in one of your papers) as a rudiment or representation of the Uterus.6 I am sure I have read (& hope to find the reference,) some recent observations of the existence of both testes & ovaria at early embryonic age in both sexes of the higher animals.7 Do you know anything on this head?
(5) Is any other gland rudimentary in mankind, besides the mammary glands in male mammals?8
(6) I may add that I have alluded to traces of the supra-condyloid foramen in humerus of man;9 & to the nictitating membrane. By the way do you chance to remember whether the nictitating membrane is well developed in Marsupials?10
Pray forgive me, if you can, for being so very troublesome, & believe me, my dear Sir | Yours sincerely obliged | Ch. Darwin
Requests information about rudimentary muscles and organs in man. Asks about marrow of os coccyx, and about testes and ovaria in early embryos of both sexes.
Please cite as
Darwin Correspondence Project, “Letter no. 5362,” accessed on 12 February 2016, http://www.darwinproject.ac.uk/DCP-LETT-5362