From Daniel Oliver   23 November 1860

My dear Sir

D^r. Hooker has given me your memorandum about the Fly-Catcher.¹ Looking again at the notice of Asclepias in Konig & Sims’ Annals of Botany.² I find reference there to an account of the Fly-catching Dogbane (Apocynum androsaemifolium) by Curtis in Bot. Mag. 280.³ This is doubtless the plant. D^r. Hooker recollects it I think at Glasgow. & I believe quite thinks yours must have been the same. Curtis says “The flowers of this Apocynum have a sweet honey-like fragrance, which perfumes the air to a considerable distance x x x x when a plant x x is fully blown one may always find flies caught in its blossoms, usually by the trunk, very rarely by the leg x x x —. x x x x x x the sweet viscid substance    x    secreted by the stigma within the antherae x x the fly endeavours to obtain, & to this end insinuates its trunk first into the lowermost & widest part of the slit, betwixt each of the antherae x x pushing it of necessity upwards: when gratified, not having the sense to place itself in the same position, as that in wh. it stood when it inserted its trunk & to draw it out in the same direction downwards, unfortunately for it, it varies its position, & pulling its trunk upwards, draws it into the narrow part of the slit, where it becomes closely wedged in, & the more it pulls the more securely it is caught,” &c &c

See also Darwin (!) Botanic Garden, Supplement. p— ?. ⁴

Shall I copy you all Curtis’ account? We must make a point of looking at this Apocynum. Yours very faithfully | Dan^l. Oliver