. Comparative anatomy of the vegetative organs of the phanerogams and ferns;. Plant anatomy; Ferns. 45° PRIMA RV ARRANGEMENT OF TISSUES. Where the pith is permanent, e. g. in the stems of of Ferula and the of Imperatoria Ostruthium \ the passages may be scattered through the whole pith. In the numerous species with internodes which become hollow they are to the persistent periphery of the pith (Anthriscus vulgaris, Myrrhus, Carum Carv, Heracleum sp ) If they are originally formed in the middle, and this is a pomt which is not decided, they disappearwiththecellsofthepith
. Comparative anatomy of the vegetative organs of the phanerogams and ferns;. Plant anatomy; Ferns. 45° PRIMA RV ARRANGEMENT OF TISSUES. Where the pith is permanent, e. g. in the stems of of Ferula and the of Imperatoria Ostruthium \ the passages may be scattered through the whole pith. In the numerous species with internodes which become hollow they are to the persistent periphery of the pith (Anthriscus vulgaris, Myrrhus, Carum Carv, Heracleum sp ) If they are originally formed in the middle, and this is a pomt which is not decided, they disappearwiththecellsofthepithsurroundingthem. In some cases however, the passages persist in the middle of stems which become hollow, either surrounded by some layers of pith-cells, and standing freely and singly in the hollow (Smyrnium Olusatrum), or em- bedded in permanent lamells of pith, which extend from the periphery into the hollow (Heracleum Sphondylium). , . â . i ⢠The passages described run through the internodes as a rule with a straight, longi- tudinal course, and few branches or anastomoses. There are, however, numerous branches at and near to the nodes, by which all anastomose one with another, and are extended into the leaves and axillary shoots. Blind endings have not been ob- served. Also the sacs described in the old rhizome of Imperatoria are only huge dilatations of the passages. The passages have a similar distribution in the petiole to that in the stem. Anastomoses, even of reticulate form, occur at the points of insertion of the segments of divided or compound leaves. The branches finally enter the lamina. Here, according to Trecul's observations «n Angelica silvestris, Opoponax, Impe- ratoria, Smyrnium, Ferula tingitana, Lagoecia, &c., and also in Eryngiura, they accompany the vascular bundles, in such a way that they traverse the nerve both on the upper and on the under side, in the latter position they are on the average larger and more numerous ; there is one in eac
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Keywords: ., bookcentury1800, bookdecad, booksubjectplantanatomy, bookyear1884
