Finds JL’s facts on the diving insect that remains four hours under water new and interesting [see "On two aquatic Hymenoptera", Trans. Linn. Soc. Lond. 24 (1864): 135–42].

On ACR’s paper on glacial origin of lakes. CD thinks it is correct. Suggests further investigation to corroborate it. His only doubt has to do with areas of great activity.

On ACR’s view of cause of glacial period: CD did battle with Hooker on same point.

T. F. Jamieson has smashed CD’s Glen Roy marine theory in splendid style.