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Show 300 GYNO-DHEOIOUS PLANTS. CnAr. VII. corolla, and their anthers do :not contain any sound pollen ; but after long search I found a single plant with the stamens moderately exserted, and their anthers contained a very few full-sized grains, together with a multitude of minute e1npty ones. In some fe1nales the stamens are extremely short, and their minute anthers, though divided into the two normal cells or loculi, contained not a trace of pollen: in Dthers again the anthers did not exceed in dimneter the filaments which supported the1n, and wore not divided into two loculi. Judging fron1 what I have myself seen and from the descriptions of others, all the plants in Britain, Gern1any, and near Mentone, are in the state just described ; and I have never found a single flower with an aborted pistil. It is, therefqre, rmnarkable that, according to Delpino,* this plant near Florence is generally trimorphic, consisting of males with aborted pistils, females with aborted stamens, and herma phrocli tes. I found it very difficult to judge of the proportional number of the two forms at Torquay. They often grow mingled together, but with large patches consisting of one form alone. At first I thought that the two were nearly equal in nu1nber; but on examining every plant which grew close to the edge of a little overhanging dry cliff, about 200 yards in length, I found only 12 fe1nales; all the rest, some hundreds in number, . being hermaphrodites. Again, on an extensive gently sloping bank, which was so thickly covered with this plant that, viewed from the distance of half a mile it appeared of a pink colour, I could not discover a single female. Therefore the her- * ' Sull' Opera, la Dist.ribnzione dei Sessi nelle Piante, &c.' 1867 p. 7. With respect to Germany: H. 1\fiiller, 'Die Befruchtung, &c.,' p. 327. CHAP. VII. GYNO-DICEOIOUS PLANTS. 301 maphrodites must greatly exceed in number the females, at least in the localities examined by me. A very dry station apparently favours the presence of the female form. With so1ne of the other abovenamed Labiatro the nature of the soil or climate likewise seems to determine the presence of one or both forms; thus with Nepeta glechmna, Mr. Hart found in 1873 that all the plants which he examined near Kilkenny in Ireland were females ; whilst all near Bath were hermaphrodites, and near Hertford both fonns were present, but with a preponderance of hermaphrodites.* It would, however, be a mistake to suppose that the nature of the conditions determines the form independently of inheritance ; for I sowed in the same small bed seeds ofT. serpyllum, gathered at Torquay from the female alone, and these produced an abundance of both forms. There is every reason to believe, fro1n large patches consisting of the same form, that the same individual plant, however much it may spread, always retains the same form. In two distant gardens I found masses of the lemon-thyme (T. citriodorus, a var. of T. serpyllum), which I was informed had grown there d \Iring many years, and every flower was female. With respect to the fertility of the two forms, I n1arked at Torquay a large hennaphrodite and a large female plant of nearly equal sizes, and when the seeds were ripe I gathered all the heads. The two heaps were of very nearly equal bulk ; but the heads from th~ female plant numbered 160, and their seeds wmghed 8 · 7 grains; whilst those from the hermaphrodite plant nu1nbered 200, and their seeds Weighed only 4· 9 grains; so that the seeds from the * 'Nature,' June 1873, p. 162. |