Sends first three of his Lectures to working men [on our knowledge of the phenomena of organic nature (1863)]. Does not intend them to be widely circulated.

On THH’s Lectures to working men.

Work by Ferdinand J. Cohn on the contractile tissue of plants ["Über contractile Gewebe im Pflanzenreich" Abh. Schlesischen Ges. Vaterl. Cult. 1 (1861)] seems important. CD has come to the conclusion that there must be some substance in plants analogous to the supposed diffused nervous matter in lower animals.

[Part of P.S. missing from original.]

Enthusiastic about Lectures IV and V [Lectures to working men (1863)].

Sends specific comments on fantail pigeon,

sterility of hybrids,

the geological section diagram.

Returns Kingsley’s letter [see ML 1: 225 n.].

Lectures [to working men] would do good if widely circulated.

On sterility, they differ so much there is no use arguing. To get the degree of sterility THH expects in recently formed varieties seems to CD simply hopeless. Has suggested a test experiment to Tegetmeier [two fertile birds paired and unproductive].