Glad THH has taken up aphid question versus Owen ["On the agamic reproduction and morphology of Aphis", Trans. Linn. Soc. Lond. 22 (1858): 193-236].

Fertilisation and inheritance discussed. Speculates that fertilisation may be a mixture rather than a fusion. Can understand in no other way why crossed forms tend to go back to ancestral forms.

His thanks for the pamphlet ["Remarks on the final causes of the sexuality of plants" (1860)] and the extremely kind and liberal manner in which Daubeny alludes to CD's work.

Further discussion of sexual generation and CD's suspicion that its most important function remains hidden.

Pleased that Bentham is cautious about Naudin's view of reversion. CD can show experimentally that crossing of races and species tends to bring back ancient characters.

Suggests Gärtner's Bastarderzeugung [1849] be translated

and that Oliver review Scott's Primula paper [J. Linn. Soc. Lond. (Bot.) 8 (1865): 78-126] for a future issue of Natural History Review.

Is working on Variation.

He has finished MEW's work on hybrid willows [Die Bastardbefruchtung im Planzenreich (1865)] and sends his thanks. The extreme frequency of hybrid willows is new to CD, and he finds the explanation of their numbers in certain locations ingenious.

Comments on the criticism of Gärtner's view of reversion

and the differences between MEW and Naudin.

CD now has doubts regarding his own view that hybrids are sterile from not being perfectly accommodated to their conditions of life.

Glad to read what CD sends. Any glimmer of light on those subjects is of utmost importance.

Quotes a letter from Haeckel on progress of Darwinism in Germany.