From John Struthers 31 December 1864
Decr 31 1864.
Allow me to ask your acceptance of Part II of my Anatomical Papers,1 on account especially of the last (on variation in the number of Fingers & Toes, and in the number of Phalanges, in Man) which may possibly interest you.2 The next last Paper may perhaps also interest you as indicating a physical cause for the preference of the right hand by all known races of Man.3
I have to thank you for your reference in April last4 to De Blainville’s notice of the Solid Hoofed Pig.5 It is also I find noticed by Otto in his great work on Monsters (page 314, Section 551—Figured in Table XXI Figs: 8 & 9, and the hoofs in Figs: 10. 11. 12).6 Also in his compendium of Comparative Anatomy (Translated by South), page 118.7 Prof Retzius of Stockholm8 informed me last year that there is not now there any specimen or knowledge of the variety, notwithstanding Otto’s reference to Stockholm.9
Otto also gives cases (cases 465, 466, 467—468 and 469—and Tab: XXVI Fig 1 of five or more toes in the Pig.10
I am desirous of drawing your attention to the occurrence of a supra-condyloid process in the human arm, a variety which early attracted my notice and which seems to me of much interest in relation to the subject of variation and Rudimentary Structures. I had kept the enclosed notice of it, from the Lancet with the view of asking your acceptance of it,11 but the many duties connected with my removing from Edinburgh to Aberdeen have caused delay.12
If at any time you would like to see some of my now numerous specimens of the supra-condyloid variety in Man, or my specimen (referred to on page 231 footnote) of Pig’s foot with five toes, it would afford me much pleasure to forward them for your inspection.13
With much respect I am | Yours faithfully | John Struthers
Charles Darwin Esq
Sends CD part two of his anatomical papers [Anatomical and physiological observations (1863) [part 1 (1854)]]; thinks CD may be interested in the paper dealing with variation in numbers of digits in man. Draws CD’s attention to another variation: the occurrence of a supra-condyloid process in the human arm.