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Show 246 CONCLUDING REMARKS 0IIAP. VI. TABLE 33. Fertility of the Legitimate Unions taken together, compared with that of the Illegitimate Unions together. '17w f eTtility of the Legitimate Unions, as Judged by both standards, is tal.;;en as 100. Illegitimate Unions. 1- --------- Primula veris P. elatior. . P. vulgaris . Name of Species. P. Sinensis . . . . P. Sinensis (second trial) P. Sinensis (Hildebrand) P. auricula (Scott) . P. Sikkimensis , P. cortusoides , P. involucrata , P. farinosa , . . . • • . . Average of the nine species of Primula . Hottonia palustris (H. l\1Uller). . . . . ti~ urn grandiflorum (the difference probably} 1s much greater) . • • . • • . . J.. .. perenne • . • . I.. perenne (Hildebrand) • • • • • • Pulmonaria officinalis (German st.ock.' H•ilde.-} brand). • • • Pulmonaria angustifolia Mitch ella repens. . . "'Borreria, Brazilian sp. . Polygonum fagopyrum • Lythrum salicaria . . . • Oxalis Valdiviana (Hildebrand). 0. Regnelli , • 0. speciosa • • Proportionnl Number of Flowf·rs which pro. duced Capsules. 69 27 60 84 0 100 80 95 74 72 71 88•4 0 0 35 20 33 2 0 15 Average Numh~r of f-5ecds per Capsule. 65 75 54 63 53 4-2 15 31 66 4-8 44 69 61 69 20 0 0 32 47 0 46 46 34 0 49 the two sexes of dimcious plants. Nor does the calyx differ, but the corolla sometimes differs slightly in shape, owing to the different position of the anthers. In Borreria the hairs within the tube of the corolla are differently situated in the long-styled and short-styled forms. In Pulmonaria there is a slight difference in the size of CHAP. VI. ON HETEROSTYLED PLANTS. 247 the corolla, and in Pontederia in its colour. In the reproductive organs the differences are 1nuch greater and more important. In the one form the stamens may be all of the same length, and in the other graduated in length, or alternately longer and shorter. The filaments may differ in colour and thickness, and are so1netimes nearly thrice as long in the one form as in the other. They adhere also for very different proportional lengths to the corolla. The anthers someti1nes differ much in size in the two forms. Owing to the rotation of the filaments, the anthers, when mature, dehisce towards the circumference of the flower in one fonn of Faramea., and towards the centre in the other form. The pollen-grains sometimes differ conspicuously in colour, and often to an extraordinary degree in diameter. They differ also somewhat in shape, and apparently in their contents, as they are unequally opaque. In the short-styled form of Faramea the pollen-grains are covered with sharp points, so as to cohere readily together or to an insect ; whilst the smaller grains of the long-styled form are quite smooth. With respect to the pistil, the style may be almost thrice as long in the one form as in the other. In Oxalis it sometimes differs in hairiness in the three forms. In Linum the pistils either diverge and pass out between the filaments, or stand nearly upright and p~rallel to them. The stigmas in the two forms often differ much in size and shape, and more especially in the length and thickness of their papillre; so that the surface may be rough or quite smooth. Owing to the rotation of the styles, the papillose surface of the stigma is turned outwards in one form of Linum perenne, and inwards in the other form. In flowers of the same age of Primula veris the ovules are larger in the long-styled than in the short-styled form. The |