Studying self-sterility, particularly in Oncidium, where abortion occurs consistently but stigma functions normally. His hybrid orchid crosses show sterility occurs capriciously. Thus it is not a "special endowment".

Disputes Asa Gray’s and Hermann Crüger’s view of rostellar germination.

Doubts absolute sterility of Catasetum.

Disappointed by results with homomorphic cowslips.

Thanks for CD’s Linum paper [Collected papers 2: 93–105].

Has not published much because he would be ignored as a gardener; hence he is looking for a foreign appointment.

Has prepared orchid sterility paper at CD’s suggestion [Trans. Bot. Soc. Edinburgh 7 (1863): 543–50].