. Botany for high schools and colleges. Botany. 434 BOTAl^Y. About tMs time there is in most cases a slight differentiation of the inner cells, foreshadowing the future tissue sys- tems {III. and IV., Fig. 310). A little later the cot- yledons (one or two) appear; in the Monocotyle- dons, in one side of the thallus - like structure a depres- sion forms, which becomes the punc- tum vegetationis of the embryo, and marks the limits of the stem and single cotyledon ; in the Decotyledons two cotyledons grow out symmetrically from the distal end of the thallus-like structure, and the depression betw
. Botany for high schools and colleges. Botany. 434 BOTAl^Y. About tMs time there is in most cases a slight differentiation of the inner cells, foreshadowing the future tissue sys- tems {III. and IV., Fig. 310). A little later the cot- yledons (one or two) appear; in the Monocotyle- dons, in one side of the thallus - like structure a depres- sion forms, which becomes the punc- tum vegetationis of the embryo, and marks the limits of the stem and single cotyledon ; in the Decotyledons two cotyledons grow out symmetrically from the distal end of the thallus-like structure, and the depression between Pig. 310.âDevelopment of the embryo of Oapsdla them beCOmeS the 5ws'i-»astoris(highly maKiiifled). /.. t), Mispensor, or ââ,ââi.,m t pro-embryo of five cells, and terminated bv a fonr-celled pUThClUnl V&g6tCt~ embryo; 1-1. the longitudinal wall which divided the ///ir/^e first embryo-cell into two cells; 3-3. transverse wall ^*t>/iAA which divided each cell of the two-celled embryo, mak- ing it four celled. IL, v. suspensor; A, thf hypophysis, the basal part of the embryo formed by the division of the end cell of the suspensor ; the shaded portion of the embryo is the dermatog«-n or primary epidermis ///., the CmbrVO form- embryo further advanced; the inner shaded cells con- . â¢' Btiiute the plerome, between these and the dermatogen eu : its Cap (the pil- to the right and left are the cells of the periblem ; the , . % . i , hypophysis is divided into two cells. A, h'. IV., still COrlllza) IS develop- older condition. F-, embryo considerably advanced; j j» ^ i « c, c. cotyledons ; «, apex of stem ; the dermatogen, perl- eCl Irom a layer 01 blera, and plerome shown as before ; w, the rudiment- âânâ ââââ j* ary root, and root-cap formed from the cell h' of III. CCUS resulting IrOm ^^^ SUCCeSsivG â fis- sion of the penultimate cell of the suspensor, the hypophy-. {V; Fig. 310). The root is the last portion of. Plea
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1888
