Sends his paper on "Willow-galls" [Proc. Entomol. Soc. Philadelphia 3 (1864): 543–644].

Lengthy criticism of Agassiz’s views on species as stated in his Essay on classification [1857].

Interested by CD’s trimorphism in Lythrum. Thinks some great mystery may lie in the fact that in some genera, some species are tri-, some di-, and some monomorphic, and in other genera, Apis, Vespa, Bombus, all the known species are dimorphic.

Comments on BDW’s papers ["On certain entomological speculations of the New England school of naturalists", Proc. Entomol. Soc. Philadelphia 3 (1864): 207–49; "On insects inhabiting the galls of certain species of willow", ibid. 3 (1864): 543–644]; much is new to CD.

Asks about wide-ranging insect genera,

Rocky Mt. wingless insects,

willow hybrids,

galls,

and other subjects.