Thanks for CGS’s work [“Über Schneckenaugen” (1877)].

Offers to give CGS a writing machine.

Pleased CGS will accept machine.

Discusses views of Moritz Wagner on modification of species. Two different cases: one in which a species is modified in the same country and cases in which a species splits. Glad CGS is taking up subject.

Discusses effect of isolation on species modification and the views of Moritz Wagner on the subject.

Discusses CGS’s account of Pellew Islands. Still believes atolls and barrier reefs in Pacific indicate subsidence. But cases like Pellew Islands, if frequent, would make his conclusions of little value.

Comments on CGS’s The natural conditions of existence [1881] and on views of Moritz Wagner on geographical distribution.

Discusses cause of variability.

Thinks CGS right not to reply to critical article by Lankester.

Discusses direct action of environment as cause of variability; the finding of Hermann Hoffmann that direct action of environment affects plants very little.