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Show I 234 ZEA MAYS. CHAP. VI. also anemophilous, or is fcrtj]iscd hy the wind; and of su ch pl~nts only the common beet had been tried. S?me plants \vcre .rmse<l in the greenhouse, an~ were crossed ':1th p~llon take~ fro~ a distinct plant; and a smgle plant, grow1ng quit? .sop~ra lcl y m a different part of the house, was allowed to fortihs~ 1tsel f spontaneously. The seeds thus obtained were placed on damp sand, and as they germinated in pairs of equal age wore planted on the opposite sides of four very large pots; n~verthel ess they wore considerably crowded. The pots were kept 1n the hothouse. The plants were :first measured to the tips of their leaves when only between 1 and 2 feet in height, as shown in the following tal>le :- TABLE XCVII. Zea may.c:, No. of Pot. Crossed Plants. Self-fertilised Plants. - -- Inches. Inches. I. 2s a 17 ~ 12 20 ~ 21 20 - II. 22 20 19~ 18 ~ 21.g 18 ~ - -·- --- III. 22A 18 ~ 20~ 15 ~ 18~ 16a 2q 18 23~ ·16g --- --- -- IV. 21 18 22~ 1 2~ 23 1s a 12 18 --- -- Total in inches. 302•88 263·63 The :fifteen crossed plants here average 20 ·19, and tho fifteen self-fertilised plants 17 ·57 inches in height; or as 100 to 87 · Mr. Galton made a graphical representation, in accordance with the method described in the introductory chapter, of the above male flowers usually shed their pollen before the female flowers arc mature: 'l\iottatsberioht d<..:r K. Akad.' Berlin, Oct. 18721 p. 743. CHAP. VI. PHALARIS CAN ARlEN SIS. 235 measurements, and adds the words" very good" to the curves thus formed. Shortly afterwards one of the crossed plants in Pot I. died ; another became much diseased and stunted ; and the third never grew to its full height. They seemed to have been all injured, probably by some larva gnawing their roots. Therefore all the plants on both sides of this pot were rejected in the subsequent measurements. \Vhen the plants were fully grown they were again measured to the tips of the highest leaves, and the eleven crossed plants now averaged 68 ·1, and the eleven selffertilised plants 62 · 34 inches in height; or as 100 to 91. In all four pots a crossed plant flowered before any one of the self-fertilised; but three of the plants did not flower at all. Those that flowered were also measured to the summits of the male flowers : the ten crossed plants averaged 66 ·51, and the nine self-fertilised plants 61· 59 inches in height; or as 100 to 93. A large number of the same crossed and self-fertilised seeds were sown in the middle of the summer in the open ground in two long rows. Very much fewer of the self-fertilised than of the crossed plants produced flowers; but those that did flower, flowered almost simultaneously. When fully grown the ten tallest plants in each row were selected and measured to the tips of their hjghest leaves, as well as to the summits of their male flowers. The crossed averaged to the tips of their leaves 54 inches in height, and the self-fertilised 44 · 65, or as 100 to 83; and to the summits of their male flowers, 53· 96 and 43 · 45 inches; or as 100 to 80. PHALARIS OANARIENSIS. Hildebrand has shown in the paper referred to under the last species, that this hermaphrodite grass is better adapted for cross-fertilisation than for self-fertilisation. Several plants were raised in the greenhouse close together, and their flowers were mutually intercrossed. Pollen from a single plant growing quite separately was collected and placed on the stigmas of the same plant. The seeds thus produced were self-fertili~ed, for they were fertilised with pollen from the same plant, but it will have been a mere chance whether with pollen from the same flowers. Both lots of seeds, after germinating on sand, were planted in pairs on the opposite sides of four pots, w hjch were kept in the greenhouse. When the plants were a little over a |