- Hope Entomological Library, Oxford University Museum of Natural History: ARW 45
- Hope Entomological Library, Oxford University Museum of Natural History: ARW 45
- Marchant, J. (Ed.). (1916). In: Alfred Russel Wallace; Letters and Reminiscences. Vol. 2. London & New York: Cassell & Co. [pp. 54-55]
Regarding Poulton's paper on the colours of larva pupae. About Darwin's ill-heath - did his children inherit it?.