. Outlines of botany for the high school laboratory and classroom (based on Gray's Lessons in botany) Prepared at the request of the Botanical Dept. of Harvard University. Botany; Botany. THJ£ LEAF 81. matters to and from the leaf stalk is most easily per- formed; and that floating leaves are free tij acquire this shape because tliey do not oversliade one another. 136. Again, the rounded forms are plainly better bal- anced, ride the waves better, and are less likely to be tipped and partially submerged. It is im- portant that the upper surface of floating leaves should be kept free, as is sho
. Outlines of botany for the high school laboratory and classroom (based on Gray's Lessons in botany) Prepared at the request of the Botanical Dept. of Harvard University. Botany; Botany. THJ£ LEAF 81. matters to and from the leaf stalk is most easily per- formed; and that floating leaves are free tij acquire this shape because tliey do not oversliade one another. 136. Again, the rounded forms are plainly better bal- anced, ride the waves better, and are less likely to be tipped and partially submerged. It is im- portant that the upper surface of floating leaves should be kept free, as is shown by the fact that they are coated with a waxy substance which prevents wetting, and which causes water thrown upon the leaves to roll away in all direc- tions. The pores whicli 1 â , 1 ⢠-1 (l(j. Leaf of llie Talii") Tree (Liriodendron). admit carbonic acid gas ' and oxj'gen are in this upper surface. Th(; circular Ijliide with the petiole attached near the center is well adapted to Iceeping every part afl<.iat. 137. The influence of the mode of fold- ing of the blade in the bud on its final sliape is well illustrated by the leaf of the Tulip tree (^Liriodendron, Fig- 60). The end of tlie lamina is seen to be cut off, as it were, or truncate. There are also pro- jections, or loheis, on either side. Figure 68 shows liow the lobes, and recesses, and the truncation lit tlie space which the very young blade occupies between and around other parts of the dc\eloping bud. Fig- ure 67 shows the blade, witli its two nr. Winter bud o£ lialvcs flatly folded together, in the win- ter bud. 138. The benefit of equal illumination fur all the leaves may well be the causi' Winter bud of Liriodendron, with some of the outer scales turned back. OUT. OF EOT. 6. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
