From W. G. Walker 21 August 1873
Summary
African elephants cry when distressed.
| Author: | William Gregory Walker |
| Addressee: | Charles Robert Darwin |
| Date: | 21 Aug 1873 |
| Classmark: | DAR 181: 4 |
| Letter no: | DCP-LETT-9020 |
From W. G. Walker 6 December 1874
Summary
On voluntary vomiting. Dogs re-swallow vomited food.
| Author: | William Gregory Walker |
| Addressee: | Charles Robert Darwin |
| Date: | 6 Dec 1874 |
| Classmark: | DAR 181: 5 |
| Letter no: | DCP-LETT-9745 |
