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Show 314 FERTILITY OF CROSSED CHAP. IX. number of the capsules alone. Nevertheless, in the more interesting cases, the seeds were also counted or weighed. The average number of seeds per c.apsnle is a more valuable criterion of fertility than the number of capsules produced. rrhis latter circumstance depends partly on the size of the plant; and we know that crossed plants are generally taller and heavier than the self-fertilised ; but the difference in this respect is rarely sufficient to account for the difference in the number of the capsules produced. It need hardly be added that in the following table the same number of crossed and self-fertilised plants are always co1npared. Subject to the foregoing sources of doubt I will now give the table, in which the parentage of the plants experimented on, and tho manner of determining their fertility are explained. Fuller details may be found in the previous part of this work, under the head of ea~ch species. TABLE D.-Relative Fertility of Plants of crossed and self-fertilised Parentage, both sets being f ertil-ised in the smne manner. Fertility y'udged of b,y various Standards. That of the crossed Plants taker~ as 100. lPOMCEA PURPUREA-.first genemtion: seeds per capsule} on crossed and self-fertilised plants, not growing mu~h as 100 to 99 crowded, spontaneously self-fertilised under a net, 1n number • • . . • • • . • . . · · · lPOMCEA PURPUREA-seeds per capsule on crossed and I self-fertilised pl~tnts from the same parents as in the lns~ , 93 case, but growing much crowded, spontaneously self-~ " fertilised under a net, in number . . . . · · · . IPOMCEA PURPUREA-productiveness of the same plants, as] 4} judged by the number of capsules produced, and average ,, " number of seeds per capsule . . . • . . · · Iro:vrCEA PURPUREA-third generation: seeds per capsule) on crossed and self-fertilised plants, spontaneously self- " " 9-! fertilised under a net, in number . . . . · · • · IPOMCEA PURPUREA-productiveness of the same plants,/ S5 as judged by number of capsules produced, and average " " number of seeds per capsule • . . • • · · · CHAP. IX. AND SELF-FERTILISED PLANTS. 315 TABLE D-con#nuerl. IPOMCEA PURPUREA-jijth generation : seeds per capsule ]I on crossed and self-fertilised plants, left uncovered in the as 100 to 89 hothouse, and spontaneously fertilised . . . . • . IPOMCEA PURPUREA -ninth generation : n urn ber of capsules l on crossed plants to those on self-fertilised plants, spon- , , 26 taneously self-fertilised under a net . . . . . . tion crossed by a fresh stock, and on phlants ofb the 1 9tfb , , 30 MrMULUS LUTEUS-an equal number of capsules on plants~ descended from self-fertilised plants of the 8th genera-self- fertilised generation, both sets aving een e t uncovered and spontaneously fertilised, contained seeds, by weight • . • . . • . . . . • . . MIMULUS LUTEUS-productiveness of the sa~e plants, as~ judged by number of capsules produced, and average . , , 3 weight of seeds per capsule. . . . . . • . VANDELLIA NUMMULARIFOLIA-seeds per capsule from] cleistog~me flowers on the crossed and self-fertilised plants, m number . • • • . . • . · · · SALVIA COCCINEA-crossed plants, compared with self-fer-} tilised plants, produced flowers, in number . . . . IBERIS UMBELLATA-plants left uncovered in greenhouse ;1 intercrossed plants of the 3rd generation, compared with ~elf-fertilised plants of the 3rd generation, yielded seeds, In number • . • . . . . • • · • · · lBERTS UMBELLATA-plants from a cross betwePn two) varieties, compared with self-fertilised plants of the 3rd generation, yielded seeds, by weight . . . . • . PAPAVER VAGUM-crossed and self-fertilised plants, left} uncovered, produced capsules, in number • . . • . ESCHSCIIOLTZIA CALIFORNICA-Brazilian stock; plants left uncovered and cross-fertilised by bees ; capsules on iptercrossed plants of 2nd generation, compared with capsules on self-fertilised plants of 2nd generation, contained seeds, in number. ESCI-ISCIIOLTZIA CALIFORNICA-productiveness of the same] plants, as judged by number of capsules produced, and average number of seeds per capsule . . • • . • ESCIISCI-IOLT~IA CALIFORNICA-plants left uncov.ered andl cross-fertilised by bees: capsules on plants clenved from intercrossed plants of 2nd generation of the Brazilian stock crossed by English stock, compared with capsules on self-fertilised plants of 2nd generation, contained seeds, in number. . . . . • · · · · · • ESCI-JSCHOLTZIA CALIFORNICA-productiveness of the same) plants, as judged by number of capsules produced, and average number .of :?eed;; per capsule . .• . • • . " " 106 " " 57 " " 75 " " 75 " " 99 " " 78 " " 89 " " 63 " " 40 |