. The Bible and science. Fig. 33.—Scale of Scotch fir-bearing ovules. are produced, but in all other flowering plants theovules are produced within a special structure, whichwe may compare to the womb of an animal, called theovary. All the higher plants, all those which are produceddirectly from seed, are divided into two classes ; gymno-sperms, in which the ovule is naked, and angio-sperms, in which the ovule is formed within the class of gymnosperms contains only the pines andcycads, and plants closely allied to them ; all otherflowering plants are angiosperms. The seeds grow w^ith
. The Bible and science. Fig. 33.—Scale of Scotch fir-bearing ovules. are produced, but in all other flowering plants theovules are produced within a special structure, whichwe may compare to the womb of an animal, called theovary. All the higher plants, all those which are produceddirectly from seed, are divided into two classes ; gymno-sperms, in which the ovule is naked, and angio-sperms, in which the ovule is formed within the class of gymnosperms contains only the pines andcycads, and plants closely allied to them ; all otherflowering plants are angiosperms. The seeds grow w^ithin the ovary until they haveattained maturity, and then, by its bursting or 88 THE OVAEY. destruction they are set free and scattered abroad. Theovary is generally a more or less egg-shaped or globularhollow vessel, attached at one end, and sending offat the other one or more prolongations called styles,. Fig. 34.—Vertical section of flower of China primrose, sliowing ovary with ovules. each of which is terminated by a somewhat flat orclub-shaped appendage covered with ghitinous fluid,and called a stigma. The little mass of cellular tissuein the interior of the ovary from which the vesselsspring is called the placenta, just like the nutritivestructure to which the embryo is attached in thewomb of an animal. In the case of ovules growing within the ovary,it is impossible for the pollen to come directly incontact with them as it can with the naked ovulesof gymnosperms. When extruded from the anthersit falls upon the glutinous sticky surface of the FERTILIZATION OF OVULES. S9 stigma, and at once the pollen tube begins to growfrom the pollen grains, and penetrates through the
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectnaturalhistory, booky
