In the July 1880 issue of Kosmos, Müller had written an essay review of Gaston Bonnier’s Les nectaires: étude critique, anatomique et physiologique (Nectaries: a critical anatomical and physiological study; Bonnier 1879a) titled ‘Gaston Bonniers angebliche Widerlegung der modernen Blumentheorie’ (Gaston Bonnier’s supposed refutation of modern floral theory; H. Müller 1880b). In the highly critical article, Müller dismissed Bonnier’s study as mere teleological speculation and a chain of logical errors.

Bonnier had observed that in Reseda odorata (mignonette), nectar produced on the underside of the disc, which was abundant when the flower opened, was reabsorbed after fertilisation (Bonnier 1879a, pp. 108–9).