Headley informs Ewart that the Fabian Society have asked him to lecture on the bearing of Weismannism on modern social questions. He challenges Ewart's statement that enfeeblement in pigeons can be traced to an illness in the parents at the time of conception as being more allied to Lamarckism. Headley suggests that this is more likely to be due to lack of food supply to the egg.

The date on the letter does not include a year, but another hand has noted '[1903?]'