Sends Hibiscus

and enclosure [Queries about expression?] on chance of "any point being observed" in Morocco.

Murray informs him edition of Descent will probably be 6500 copies.

Thanks WO for his reply to letter of 26 March. Has tried several people and platysma seemed to act, but it is difficult to observe when they shudder.

Effects of first impregnation on litters from subsequent pregnancies.

Power of selective breeding to produce different varieties.

Answers to CD’s queries will take time. CD may not be aware of the influence of accommodation on the diameter of the pupil of the eye. Parrots, for example, contract or dilate the pupil independently of amount of light [see Expression, p. 304]. Sends his book on the subject [On the anomalies of accommodation and refraction of the eye (1864)].

Asks whether capillary circulation is ever influenced by the mind’s being directed intently to any part of the body.

Has JC-B ever seen idiots blush? JC-B’s MS on blushing is capital.

Note on errata in first volume of Descent.