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Show 290 DICECIOUS AND CIIAP. VII. that some of the bushes were in function exclusively 1nales. Thirteen bushes growing near one another in a hedge consisted of eight females quite destjtute of pollen and of five hermaphrodit~s with well-developed anthers. In the autumn the eight females were well covered with fruit, excepting one, which bore only a moderate number. Of the five hermaphrodites, one bore a dozen or two fruits, and the remaining four bushes several dozen; but their number was as nothing compared with those on the female bus~es, for a single branch, between two and three feet 1n length, from one of the latter, yielded more than any ono of the hermaphrodite bushes. The difference in th~ amount of fruit produced by the two sets of bushes :s all. t~e more striking, as from the sketches ab~ve given It IS obvious that the stigmas of the polleniferous .flowers can hardly fail to receive their own pollen; whilst the fertilisation of the female flowers depends on pollen being brought to them by flies ~nd the smt~ller Hymenoptera, which are far from being such effiCient carriers as bees. . I now determined to observe 1nore carefully dunng successive seasons so1ne bushes grow·i ng I· n ano ther place about a mile distant. As the female bushes were so highly productive, I marked only two of them with the letters A and B, and five polleniferous bushes "'tvith the letters C to G. I may premise that the vear 1865 was highly favourable for the fruiting of all t"h e bushes especi·a lly for the pol1 e ni·1.[!e rous on es' some of which w'ere quite barren except under such fa~o~rable conditions. The season of 1864 was u~f~;~rna~6~ In 1863 the female A produced "some fruit; ~n 1 only 9 · and in 1865, 97 fruit. The female B In 1863 1 . was " c~verecl with fruit;" in 1864 it bore 28; anc m CHAP. VII. POLYGAMOUS PLANTS. 291 1865 "innumerable very fine fruits." I may add, that three other female trees growing close by were observed, but only during 1863, and they then bore abundantly. With respect to the polleniferous bushes, the one marked C did not bear a single fruit during the years 1863 and 1864, but during 1865 it produced no less than 92 fruit, which, however, were very poor. I selected one of the finest branches with 15 fruit, and these contained 20 seeds, or on an average 1 · 33 per fruit. I then took by hazard 15 fruit from an adjoining female bush, and these contained 43 seeds; that is more than twice as many, or on an average 2 · 86 _per fruit. Many of the fruits from the female bushes included four seeds, and only one had a single seed ; whereas not one fruit from the polleniferous bushes contained four seeds. Moreover when the two lots of seeds were coinpared, it was manifest that those from the female bushes were the larger. The second polleniferous bush, D, bore in 1863 about two dozen fruit,-in 1864 only 3 very poor fruit, each containing a single seed,-and in 1865, 20 equally poor fruit. Lastly, the three polleniferous bushes, E, F, and G did not produce a single fruit during the three year~ 1863, 1864, and 1865. . We thus see that the female bushes differ somewhat ~n their degree of fertility, and the polleniferous ones In the. most marked manner. W ~ have a perfect gradation from the female bush, B, which in 1865 was covered with " innumerable fruits," -through the female A, which produced during the same year 97 - th ~oug h the polleni.f erous bush 0, which produc' ed this y ear 92 f'r ·u 1· ts, t h ese, however, containing a very low average number of seeds of small size -thro11o·h th b . ' 0 e ush D, which produced only 20 poor fruit,-to. the three bushes, E, F, and G, which did not this u 2 |