. Morphology of angiosperms (Morphology of spermatophytes. Part II). Angiosperms; Plant morphology. 214 MORPHOLOGY OF AXGIOSPERMS. Fio. 99.— FunHa ovata, showing adventitious embryos; fer- tilized egg has given rise to weak proembryo of three cells: x 190.—After ; the adventitious embryos begin to develop but never mature. In Citrus the embryos are derived not only from the cells of the nucellus capping the sac, but also from those lower down, which may be separated from the sac by several cells. In Coele- bogyne, long sup- posed to be par- thenogenetic, fer- tilization never
. Morphology of angiosperms (Morphology of spermatophytes. Part II). Angiosperms; Plant morphology. 214 MORPHOLOGY OF AXGIOSPERMS. Fio. 99.— FunHa ovata, showing adventitious embryos; fer- tilized egg has given rise to weak proembryo of three cells: x 190.—After ; the adventitious embryos begin to develop but never mature. In Citrus the embryos are derived not only from the cells of the nucellus capping the sac, but also from those lower down, which may be separated from the sac by several cells. In Coele- bogyne, long sup- posed to be par- thenogenetic, fer- tilization never occurs in Europe, since only pistil- late plants are cultivated. These are not cases of apogamy, as often stated, but are evidently cases of vegetative multiplication or budding, since the em- bryos arise from sporophytic tissue. In Opuntia vulgaris (Ganong49) the ripe seed contains one large embryo and sev- eral smaller ones pressed to one side. Half ripe seeds generally show that the large embryo comes from the micropylar end of the sac, while the small ones arise from nucellar tissue. Among Cactaceae the only previously known case of polyembryony is that of Opuntia tortispina. The multiplication of em- bryos by budding from a mass- ive suspensor also occurs, and is especially common in the Lihiim ty]ie of embryogeny, in which the suspensor is strongly meristematic. In 1895 Jef- frey"" called attention to the fact thai in h'ri/lli muni in mihTl- ccuium the suspensor is a mass- ive and lobed tissue on whose free surface two to four embryos appear, onlv one persisting (Fig. loo). As in Finilia, the cells of the nucelhis are ft&ft. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Coulter, John Merle, 1851-1928; Chamberlain, Charles Joseph, b. 1863. New York, D. Appleton
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