. The Pharmaceutical era. ale plants only oc-cur. The egg cells are unfertilized, and yet withoutany stimulus from the male element the spores (corre-sponding to the seed of phanerogams) germinate in thespring and produce new plants. Similar and as notablecases occur frequently in the lower orders of plants. Not only among the lower plants but also among high-er plants has the unfertilized egg-cell produced, just aathe fertilized ovule, a new individual. One of the ever-lastings of the Alps (Gnaphalium alpinum) possesses onlypistillate flowers. The akenes nevertheloss contain goodseeds, and up
. The Pharmaceutical era. ale plants only oc-cur. The egg cells are unfertilized, and yet withoutany stimulus from the male element the spores (corre-sponding to the seed of phanerogams) germinate in thespring and produce new plants. Similar and as notablecases occur frequently in the lower orders of plants. Not only among the lower plants but also among high-er plants has the unfertilized egg-cell produced, just aathe fertilized ovule, a new individual. One of the ever-lastings of the Alps (Gnaphalium alpinum) possesses onlypistillate flowers. The akenes nevertheloss contain goodseeds, and upon germinating develop plants similar tothe parent. Other cases might be cited, as Mercurialisannua, of Central EuTope, and Coelebogyne iticifolia ofAustralia. Parthenogenesis.—This development of a new individ-ual from the unfertilized female egg cell is called Par-thenogenesis. A peculiarity of Parthenogenesis is that Fig. 121.—Castor oil seed, (c) caruncle; (r) raphe. 288 THE PHARMACEUTICAL ERA. [February 24, the indiTidual prodiice<i by an unfertilized seed is justlike that produced by a fertilized seed. There are cases tliat arise in nature which make tibisone of the most interesting and difficult problems wemeet. In Allium odorum additional embryos are some-times formed from the three cells at the other end of theembryo-sac. In the white Day Lly (Funkia ovata) th? embryo devel-ops evidently from some of the cells around the embryosac and not from the egg cell. The female egg cell dis-appears entirely. Polyembryony.—In tliis manner in the Citrus genus (towliich the orange belongs) not only is an embryo de-veloped from the egg-cell, but other embryos develop fromthe-tissues of the surrounding nucellus, thus giving anumber of in a single seed. This is called Poly-embryony. PRACTICAL STUDIES. (24) Almond Seed.—Take the commercial almond nutand remove the shell (corresponding to endocarp) enclos-ing the seed. Examine seed externally as to color,marki
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Keywords: ., bookcentury1800, booksubjectdrugs, booksubjectpharmacy, bookyear1
