Sends a pamphlet by W. R. Greg [Malthus: re-examined by the light of physiology (1868)].
Many Cucurbitaceae have smaller male than female flowers.
Has written to H. C. Watson on the counterbalance [to variation] of crossing and uniform conditions. Watson has forgotten the argument.
Has written to F. Müller on abnormal Solanum.
Does not understand Hildebrand on potatoes.