. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. PARENCHYMA OF THE LEAF-BLADE. 159. 446. The centric arrangement has two modifleations : (1) that in whicli the whole pulp is composed of chlorophyll parenchyma, but towards its mid- dle plane has larger cells with less chlo- rophyll, aud some- times has conspicu- ous lacunte (many grasses. Yucca flla- uieutosa, Crassula, etc.) ; (2) that in which it is composed of la3-ers which are uniformly distrib- uted above and be- low a middle laj'er of colorless cells fre
. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. PARENCHYMA OF THE LEAF-BLADE. 159. 446. The centric arrangement has two modifleations : (1) that in whicli the whole pulp is composed of chlorophyll parenchyma, but towards its mid- dle plane has larger cells with less chlo- rophyll, aud some- times has conspicu- ous lacunte (many grasses. Yucca flla- uieutosa, Crassula, etc.) ; (2) that in which it is composed of la3-ers which are uniformly distrib- uted above and be- low a middle laj'er of colorless cells free from chloroplyll, but, in succulents, ver}' rich in sap (Aloe, IMesembryanthemum, etc.). In both the foregoing modifica- tions the upper layer of the parenchyma may be composed of somewhat longer cells than those below, and to them can be applied the term more gener- ally given to those in the next type, namely, palisade-cells. 447. The bifacial arrangement has the (jlenser tissue in that part of tlio leaf which is exposed to the light. This usually consists of several layers of palisade paren- FlG. ]22. Leaf of Piiius Laricio. Cross-section of a part of the ]eaf, Blmwing the stoniata, hypnderraa, ami parenchyma. The fnldeil walls of the parenchvma-oells (see 208) are plainly shown in the cells below the resin-passage {TIC), where they have been emptied of their contents. (Kny.) Fig. 123. Transverse section of a leaf of Ilex Aquifolium, showing arrangement of the parenchyma: 2^p^ palisade parenchyma; pr, spongy parenchyma; /i, hypoderma; la, fibro-vascular bundle. Stomata are found only upon the lower surface of the leaf. (Areschoug.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Goodale, George L. (George Lincoln), 1839-1923. New York [etc. ] : American Book Co.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectplantanatomy, bookyea
