. Elementary botany . Fig. 273. Archegonium of Picea vulgaris, sperm cell ap- proaching the nucleus of egg cell. Fig. 274. Archegonium of Picea vulgaris showing fusion of sperm nucleus with egg nucleus. Fig. 275. Embryo of white pine re- moved from seed, showing several coty- ledons. Fig. 276. Pine seedling just emerging ground. from the Figs. 273, 274.—Fertilization in picea. (After Strasburger.) has a ligule above the sporangium, or as in ophioglossum, where the leaf is divided into a fertile and a sterile portion. A more recent view regards each cone scale as a flower, the ovuliferous scale
. Elementary botany . Fig. 273. Archegonium of Picea vulgaris, sperm cell ap- proaching the nucleus of egg cell. Fig. 274. Archegonium of Picea vulgaris showing fusion of sperm nucleus with egg nucleus. Fig. 275. Embryo of white pine re- moved from seed, showing several coty- ledons. Fig. 276. Pine seedling just emerging ground. from the Figs. 273, 274.—Fertilization in picea. (After Strasburger.) has a ligule above the sporangium, or as in ophioglossum, where the leaf is divided into a fertile and a sterile portion. A more recent view regards each cone scale as a flower, the ovuliferous scale composed of three united carpels arising in the axil of a Leaf, the cover scale. Two of the carpels are reduced to ovules, and the outer integument is expanded into the lateral portion of the scale, while the central carpel is sterile and ends in the point or mucro of the scale.
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisher, booksubjectbotany
