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Show FALLING LEAVES. H "My T: flfli The Scientific Reacon for Their BBJ If W0ri8tfwhy .ic-'nyus full, it may bo difficult 1to'flnd1i completes answer, BB but 8omo of the advantages to tho Bfl tree aro nppnrent. Tho most rigorous BH soason of tho year Is the winter, nnd BH at this tlmo most of our trees aro without leaves. Leaves aro tho most delicate parts of the tree and aro poor- Bj ly fitted to withstand tho severity of northern winters, although wo may Bfl notlco tho reduced alzo and firmer BBJ Hructuro of thoso of tho conlfors BJ which remain on tho treos during cold BBJ weather. Tho nbsenco nt loaves makes BBJ tho1 trees less expnspd 'to being ovor- turned or" broken liyMlio flerco blasts BBl V I ill i?! ' L E a E 8 ''b El N b" ctl T OFF. election of Horse-chestnut Twig En- BBJ BBl of tho winter's winds, but probably tho greatest advantage to tho tree is the very much smaller aurfaco for tho evaporation of water. During cold BHJ wenthor all plants absorb water very slowly and probably the greatest dan- BHJ ger the tree haslo Aeet during tho BBJ 'wlnterJstth"nt'.iuoro"tftter will bo lost BflJ by evaporation and transpiration than can be supplied, by absorption. Then tlio'vfal process of rood manufacture lshlmost entirely stopped by cold BHJ weather and hence tho work of the leaves may be said to bo done as the autumn temperaturo lowers. BBj Tho process by which leaves aro removed from tho trees 1b an interest-Ing interest-Ing ono, although thoy aro neither pushed off by tho nowly-formod buds nor loosened by tho frost. In order to understand tills process, It is noces- BBJ sary to examlno tho structure of tho potlolo whoro It Joins tho twig. Tho horse-chestnut shows the various parts BHJ very plainly. Tho central portion of tho fwlg Jb U .cy.Uqde.cj): jjcqody, flb.ro, which, during tho llfo of tho treo, coin- BBfl vcys tho propared food in a downward BHJ passago, tho' outer portion or flbres'of BVJ tho bark conducting tho sap In Its up-ward up-ward flow. Ono or moro strands of woody conducting fibre' passes out BHJ Into tho petiole of each leaf (A). As ftVJ the season advances nnd preparatory BH to tho falling of tho leaves n layer of BB tliln-wnllcd colls forms at tho baso of hflj tho potlolo (B). These colls aro very BBJ similar to tho cork colls found In tho bark of tho trco and check the pas- Bfl sago of nil fluids except through tho BBJ control strand of fibres.' Through ths BBJ central strand most of tho prepared BBJ food passoB from alio loaf to tho tree, Bfl tliero to bo used in growth or stored Bfl for niionthcr season, leaving in this BBJ leaf only useless waste products, As BB tho cutting off layer is completed BB many of tho culls in the center break B down nnd nothing holds the icai In BB place oxcoptlng tho fibres of the con- B trnl strum!, then n light breozo or oven B 'tho weight of tho leaf In enough to BB snap this Blonder thread nnd the leaf BB Mutters to tho ground. Tho cells which B cut off tho leaf now form a protecting BJ layer excluding all moisture from thu BB BB Trees vnry greatly with respect to B tho formation of this cutting oft, layor, BB says tho Montreal Herald; In somo BB llko tho horse-chestnut It Is thick and BB corky, being easily seen by tho naked BB oyo, In tho ash, butternut and many BB others It Is we)l dovopod, while In B some llko the beech it la scarcely B present nt all. BflflJ |