From Charles Cardale Babington   [c. June 1855]¹

Dated on the basis of CD’s annotation referring to Gärtner 1849, which he completed reading in June 1855 (DAR 116 (ser. 5): 1), and from Babington’s reference to CD having finished his cirripede work.

The questions that CD had sent to Babington, with Babington’s replies added to them, are preserved in CD’s copy of Gärtner 1849, following p. 728, in the Darwin Library–CUL. His questions related to the differing definitions of the various forms of oxlip, cowslip, and primrose: 1. P. acaulis 2 P. elatior (calycantha) 3 P. elatior (communis) 4 P. veris (officinalis) 5 P. veris (officinalis) calycantha 6 P. calycantha (elatior) N.B. in N^o 3. “communis” sometimes in Bracket, sometimes not. No 5. I presume must be some blunder of Printers no 6. Can these names have been reversed by Printer To item one, Babington added ‘P. vulgaris. Primrose. A species’. To item three, he added ‘P. elatior. Oxlip, true plant. a species’. To item four, he added ‘P. veris. Cowslip.—a species’. Below CD’s questions, Babington wrote: The plants named calycantha are forms of the several species in which the calyx has become very much enlarged and coloured to a more or less extent (usually greatly) like the corolla. The name is to be found so used in the German systematists such as Mertens & Koch Deutschl. Flora, &c. P. elatior var. calycantha was once called a species (P. calycantha) by Retz. By “communis” is mearly intended “common form”. It is not a name. No. 5. veris and officinalis are synonymous terms, each having been used to denominate the true cowslip which by Linnaeus was called P. veris a officinalis. Babington’s references are to Mertens and Koch 1829–39 and Retzius 1779–91, 2: 10.

Babington 1851, p. 258. CD’s copy is in the Darwin Library–CUL.

W. J. Hooker and Arnott 1855, p. 314. George Arnott Walker Arnott had collaborated with William Jackson Hooker on the sixth (1850) and later editions of Hooker’s British flora. A copy of the seventh edition (1855) is in the Darwin Library–CUL. See also Babington 1851, p. 231. On the inside back cover of his copy of this work, CD wrote: ‘Verbascum 5 [interl] stamens differ in length & structure—’. CD’s work on the hybridisation of oxlips, cowslips, and primroses was later written up in Natural selection, pp. 128–33. His interest in the varieties of Verbascum was primarily directed towards ascertaining the different forms of flowers on plants of the same species. See his paper on the subject ultimately published in 1862 (Collected papers 2: 45–63). Verbascum lychnitis is discussed on p. 59.

CD’s notes on Gärtner 1849, made in June 1855 (DAR 116), indicate that CD was interested in following up Gärtner’s experiments on crosses between varieties of plants. Species of Verbascum were crossed by Gärtner and the fertility of the hybrids given in a table (Gärtner 1849, pp. 724–8). White flowered varieties of V. lychnitis were also crossed with yellow flowered varieties, and Gärtner found that crosses between similarly coloured forms were more fertile than those between the differently coloured forms. This result appeared to vindicate CD’s view that crosses between varieties were not always completely fertile and that varieties could be considered as incipient species (Natural selection, pp. 405–7).