. Popular science monthly. return to the consideration of the general characteristics of tropi-cal vegetation. In illustration, however, of the present point, perhapsthe clearest evidence is afforded by some Australian species, especiallythe eucalypti and acacias. Here the adaptations which we meet withare directed, not to the courting, but to the avoidance, of light. The typical leaves of acacias are pinnate, with a number of the other hand, many of the Australian acacias have leaves (or, tospeak more correctly, phyllodes) more or less elongated or if we raise them
. Popular science monthly. return to the consideration of the general characteristics of tropi-cal vegetation. In illustration, however, of the present point, perhapsthe clearest evidence is afforded by some Australian species, especiallythe eucalypti and acacias. Here the adaptations which we meet withare directed, not to the courting, but to the avoidance, of light. The typical leaves of acacias are pinnate, with a number of the other hand, many of the Australian acacias have leaves (or, tospeak more correctly, phyllodes) more or less elongated or if we raise them from seed we find, for instance, in Acacia salicina^so called from its resemblance to a willow, that the first leaves are pin- ON LEAVES. 355 nate (Fig. 16), and differ in nothing from those characteristics of thegenus. In the later ones, however, the leaflets are reduced in number,and the leaf-stalk is slightly compressed laterally. The fifth or sixthleaf, perhaps, will have the leaflets reduced to a single pair, and the.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1872
