On nesting habits of pied and spotted flycatchers.

JPT disagrees with CD’s comment in Descent.

Marriages of first cousins produce congenital deaf-mutism.

Discusses his work [Flora fossilis Arctica, vol. 4, pt 1 (1876)].

Sends copy of [Fossile Pflanzen von Sumatra (1874)]. Comments on climate in Tertiary period, especially on Sumatra.

Comments on theory of Thomas Belt concerning climatic change in ice age.

TB, who sailed with CD [as a Royal Marine] in the Beagle, asks for CD’s portrait. Recalls some events they shared.

Is preparing a paper on the umbilical cord ["On the anatomy of the umbilical cord", Proc. R. Soc. Lond. 23 (1875): 498–501; 24 (1876): 417–40] of which he sends a preliminary note [missing]. Believes spiral growth of the umbilical cord is important evidence of the descent of man; speculates on spiral growth in general.

Has at last finished Insectivorous plants

and is rewriting Climbing plants.

W. W. Ouless has finished his picture of CD for Academy.

Has just come to London. Invites TB to luncheon.

Thanks CD for Descent

and for his praise of Cosmic philosophy [1874].