Text-book of botany, morphological and physiological . hological properties, but which differfrom true hairs in not originating from single epidermis cells, but consist of massiveoutgrowths of the tissue which lies beneath the epidermis, remaining however coveredby a continuation of it. Examples of such structures, which may perhaps be distin-guished by the term Emergences, are afforded, according to Rauter, by the prickles andglandular hairs of roses, and perhaps also of the various species of Rubus. Closelyrelated to these are probably the warts, tubercles, and knobs on the surface of manyfr
Text-book of botany, morphological and physiological . hological properties, but which differfrom true hairs in not originating from single epidermis cells, but consist of massiveoutgrowths of the tissue which lies beneath the epidermis, remaining however coveredby a continuation of it. Examples of such structures, which may perhaps be distin-guished by the term Emergences, are afforded, according to Rauter, by the prickles andglandular hairs of roses, and perhaps also of the various species of Rubus. Closelyrelated to these are probably the warts, tubercles, and knobs on the surface of manyfruits { of Euphorbiaceae, Ricinus). They resemble the leaves and branches ofPhanerogams in their origin, but hairs in their later formation, and in their occurrenceon stems as well as on leaves, and in their irregular disposition. For spines, whichmust not be confounded with prickles, cf. sect. 28. Sect. 23. The term Root^ is applied in botanical morphology, in contrastto its use in popular language, only to such outgrowths of the substance of the. Fig. no.—Longitudinal section of the youngprimary root of the embryo of Marsilea salvatrtx;TVS the apical cell, uh, Tvh, Tih the still simpleroot-cap ; x,y the last segments of the substanceof the root; z t intercellular spaces. Fig. III.—Longitudinal section of a somewhat older prhnarj- root of MarsUea salvatrix; ws apical cell; whl + Tvhl the first,whZ-ir-whi the second, wh^ the third layer of the root-cap ; each layer now consists of two divisions ; xy the youngest segmentsof the substance of the root; o epidermis; £^J fibro-vascular bundles ; h the part of the root-cap which extends furthest back. plant as are clothed at their growing apex with a layer of tissue, the Root-capalready described in sect. 19. Roots do not form leaves or other exogenous
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
