The principles of biology . in atransverse direction; and the transversemultiplication being greater towards themiddle of the frond, there residts a differ-ence between the middle and the two ex-tremities—a character which, in a feebleway, unites all the parts into a whole. Eventhis slight individuation is, however, veryindefinitely marked; since, as shown by1 the figures, the lateral multiplication of cellsI does not go on in a precise manner. From some such type as this there appearI to arise, by slight differences in the modes ofgrowth, two closely-aUied groups of plants,having individualit
The principles of biology . in atransverse direction; and the transversemultiplication being greater towards themiddle of the frond, there residts a differ-ence between the middle and the two ex-tremities—a character which, in a feebleway, unites all the parts into a whole. Eventhis slight individuation is, however, veryindefinitely marked; since, as shown by1 the figures, the lateral multiplication of cellsI does not go on in a precise manner. From some such type as this there appearI to arise, by slight differences in the modes ofgrowth, two closely-aUied groups of plants,having individualities somewhat more pro-nounced. If, while the cells midtiply lon-gitudinally, their lateral multiplication goes on in one direc-tion only, there residts a flat surface, as in Ulva linza, ; or where the lateral multiplication is less uniform in itsrate, in types like Fig. 26. But where the lateral multipli-cation occurs in two directions transverse to one another,a hoUow frond may be produced—sometimes irregularly. THE MORPHOLOGICAL COMPOSITION OF PLANTS. 19 spheroidal, and sometimea irregularly tubidar; as in Entero-morpha intestinalis, Fig. 27. And occasionally, as in Entero-morpha compressa, Fig. 28, this tubular frond becomes 29 and 30 are magnified portions of such fronds ; show-
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectbiology, bookyear1864
