RBG Kew, Letters to H. N. Ridley, vol. 4, f. 251.The MS is a pre-paid French Carte Postale, postmarked twice Le Mans Sarthe 8E | 21 Juil 93 and once Singapore Au 16 93, addressed to Mr Ridley | Director of the Botanic Garden | Singapore | Straits Settlements | Establissements Detroits. The note was not written by M but, presumably, by Hector Léveillé, and was probably written without M’s knowledge