Reports on abortive anthers in flowers of thyme sent by CD.
Hitcham Bildeston | Suffolk
21 Nov 1840
My dear Darwin,
I have examined the flowers of your Thyme— The Anthers are abortive—which is not uncommon in more than one species of the Genus— In nearly the whole Order, one stamen out of 5 is constantly suppressed, either entirely, or there remains merely a rudiment of a filament— The suppression of the 5 Anthers shews a tendency in the present species towards becoming diœcious, but I don't known whether the pistil is ever suppressed whilst the Anthers remain perfect—
I expect to be in town on
With Kindest remembrances to M
- f1 582.f1Labiatae.
- f2 582.f2This letter was kept with materials used in writing Forms of flowers (DAR 109: 86). By the time of that publication (1877), CD had decided that thyme is gyno-dioecious, i.e., has both hermaphrodite and female forms (pp. 298–303). The flower Henslow examined was a female, with aborted stamens, of the lemon-thyme (Thymus serpyllum var citriodorus). CD may be referring to the same plant in a note made on 1 June 1841: ‘Maer Examined the Lemon-thyme.— equally abortive as it was in autumn: … As we see in Hybrids that although anthers *nor filaments [interl] shrivel, yet stigma does not, so we may feel somewhat *but little [interl] less surprised at Henslow's remark that pistil does not become abortive.’ (Torn-apart notebook : 99 (DAR 109: 16)).
- f3 582.f3Frances Henslow.
- f4 582.f4Leonard Ramsay Henslow.
- f5 582.f5Henslow 1841.
- f6 582.f6CD had returned to London on 14 November (‘Journal’; Correspondence vol. 2, Appendix II), having been ill a good part of the time since August at Maer.
- f7 582.f7This note probably dates from the summer of 1841, when CD went back to Maer and again found the abortive form (see n. 2, above). It may reflect a view of variation in nature which CD particularly stressed in the 1840s: variation occurs rarely and only when conditions change (see the sketch of 1842 in Foundations). Thus flowering under autumnal conditions induces a change in the reproductive system.