Agrees with GR’s remarks on Asa Gray’s pamphlet.

New edition of Origin to appear immediately.

Fact of clubbed fingernails in cyanosis quite new to CD. Asks for information.

Thanks for explanation of cyanosis and clubbed nails.

Hopes GR will work out point about mucus tubes.

Index of Origin does not refer to variability of rudimentary organs mentioned at pp. 149, 168. Offers references to Rudolf Leuckart and to Franz von Leydig to support CD’s point.

The embryology of the vertebrate nervous system may be an exception to the law of inheritance at corresponding ages.

GR’s letter is a gold-mine.

Pleased to have Pierre Gratiolet’s comment on the embryology of greatly modified organs

and GR’s valuable cases of analogous variation.

Doubts craniologists, but recounts his father’s opinion that the shape of CD’s head was altered when he returned from the Beagle.