Text-book of botany, morphological and physiological . y which has also been observed by Hof-leister in Pieris aquilina. The first leaf is the scutiform leaf mentioned above,:hich is placed medio-dorsally ; then follow a second and third aerial leaf standingingly, after which the definite verticillate arrangement of the leaves at lengthommences at the fourth node; each whorl thereafter consists of a submerged leafpringing on the ventral side (right or left), which at once branches, and forms aift of long filaments hanging down into the water; while two other leaves haveuite flat laminae and sp
Text-book of botany, morphological and physiological . y which has also been observed by Hof-leister in Pieris aquilina. The first leaf is the scutiform leaf mentioned above,:hich is placed medio-dorsally ; then follow a second and third aerial leaf standingingly, after which the definite verticillate arrangement of the leaves at lengthommences at the fourth node; each whorl thereafter consists of a submerged leafpringing on the ventral side (right or left), which at once branches, and forms aift of long filaments hanging down into the water; while two other leaves haveuite flat laminae and spring from the dorsal side, touching the water only w4th theirnder surface (Fig. 295). These three-leaved whorls alternate, and thus form twoows of ventral submerged, and four rows of dorsal aerial leaves. Their succession1 age in the whorl, and the position of the wdiorls (antidromal among themselves)5 indicated in Fig. 290 a. The node of the stem which produces a w^horl ofiaves, is, as was shown by Pringsheim, formed of a transverse disc of the long. Fig. iiyia.—A the vegetative cone of the stein of Salvinia natans, regarded diagrammatically and looked atfrom above ; xx projection of the plane wliich divides it vertically into a right and left half; the segments are indi-cated by stronger outlines, their divisions by weaker lines ; the succession of the segments is denoted by the lettersF—P; B diagram of the stem with three whorls of leaves, its ventral side indicated by vv; w the first-formedsubmerged leaf; L\ the aerial leaf formed next; the second aerial leaf of the same whorl formed last of all betweenthe two first (after Pringsheim). egetative cone, w^hich, in its length (or height) corresponds to a half-segment, whilelach internode corresponds to the whole height of a segment. Each nodal disc, asveil as each internode, consists of cells of the right and left row of segments oflifferent ages; in Fig. 290 a an internode is formed of the segment Hon the rightide, of
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
