. Popular science monthly. those of the Spanish chestnut ( Castanea)and those of Acer platcmoides, a species of maple. I have takenspecimens in which the six terminal leaves of a shoot of the tworpecies occupy approximately the same area. Figs. 4 and 11 show theleaves in their natural position, those of Castanea lying along the stalk,while those of Acer are ranged round it. In both cases it will beseen that there is practically no overlapping, and very little waste ofspace. In Castanea the stalks are just long enough to give a certainplay to the leaves. In Acer they are much longer, bringing t
. Popular science monthly. those of the Spanish chestnut ( Castanea)and those of Acer platcmoides, a species of maple. I have takenspecimens in which the six terminal leaves of a shoot of the tworpecies occupy approximately the same area. Figs. 4 and 11 show theleaves in their natural position, those of Castanea lying along the stalk,while those of Acer are ranged round it. In both cases it will beseen that there is practically no overlapping, and very little waste ofspace. In Castanea the stalks are just long enough to give a certainplay to the leaves. In Acer they are much longer, bringing the leaves 352 THE POPULAR SCIENCE MONTHLY. approximately to the same level, and carrying the lower and outerones free from the upper and younger ones. Now, if we arrange the Spanish-chestnut leaves round a center, asin Fig. 12, it is at once obvious how much space is wasted. On theother hand, if we attach the leaves of the Acer to the stalk of Castaneaat the points from which the leaves of Castanea came off, as in Fig. 13,. Fio. 12. Fig. 13. we shall see that the stalks are useless, and even mischievous, as a causeof weakness and of waste of space ; while, on the other hand, if weomit the stalks, or shorten them to the same length as those of Cas-tanea, as in Fig. 14, the leaves would greatly overlap one another. Once more, for leaves arranged as in the beech the gentle swell atthe base is admirably suited ; but in a cx-own of leaves, such as those of the sycamore, space would be wasted, and itis better that they should expand at once assoon as their stalks have borne them freefrom those within. Moreover, the spreadinglobes leave a triangular space (Fig. 11) withthe insertion of the stalk at the apex, which-(-■i^ seems as if expressly designed to leave room^ for the pointed end of the leaf within. Hence we see how beautifully the wholeform of these leaves is adapted to the modeof growth of the trees themselves and theFig- 14. arrangement of their buds. Before we proceed to co
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1872
