Letter from Ross [Winthrop] Gilbert, Route A, Box 73, Fresno, California, U.S.A., to Mr [William Bate] Hardy, Secretary, Royal Society, Burlington House, London, W.1 Renews his thanks to the Royal Society for offering to communicate his and his wife's [ Mabel Crawley Gilbert] thesis "Origin of Species by Orthoporeutic Descent" and informs that the delay has been due to Mabel's prolonged illness, who has now passed away. Communicates that he can no longer revise the paper but that he will rewrite it and make a few changes he believes she would have approved. Forwards the thesis, commenting on the foreword being a tribute to Charles Darwin. Requests acknowledgement of receipt [enclosure not present]. 7 May 1923