The natural history of plants, their forms, growth, reproduction, and distribution; . oss,and would be only a little lower than Cologne Cathedral. That the height and girth of trees do not increase proportionately will beseen by comparing the following table with the previous one:— Name. Diameter of trunk in metres. Name. Diameter of trunk in metres. Chestnut (Castanea vulaavis) n. C ypress ( Cupressus fastiaiata) 3-2. 3. 3. 2-8. 2. 2. 1-7. 1-7. 1-6. 1-4. 1. 1. 0-9. Mexican Cedar {Taxodium Mexicanum) Decid aousCypress( Taxodium distichum)Mammoth Tree {Se
The natural history of plants, their forms, growth, reproduction, and distribution; . oss,and would be only a little lower than Cologne Cathedral. That the height and girth of trees do not increase proportionately will beseen by comparing the following table with the previous one:— Name. Diameter of trunk in metres. Name. Diameter of trunk in metres. Chestnut (Castanea vulaavis) n. C ypress ( Cupressus fastiaiata) 3-2. 3. 3. 2-8. 2. 2. 1-7. 1-7. 1-6. 1-4. 1. 1. 0-9. Mexican Cedar {Taxodium Mexicanum) Decid aousCypress( Taxodium distichum)Mammoth Tree {Sequoia gigantea) Ji\)e\e (Populus alba) Broad-leaved Lime {Tilia grandifolia)Peppermint Tree {Eucalyptus amyg- Arolla Pine (Pinus Cembra) Oak (Quercus pedunculata) Cornel (Cornus mas) ... Yew (Taxus baccata) Scotch Pine {Pinus si/lvestris) Tree of Heaven {Ailuntkus glandulosa) According to these certified estimates there actually exist plants whose stemsattain a diameter of 20 metres, and others whose stems rise to a height of14-2 metres above the ground. ERECT FOLI VGE STEMS 723. ti^ 176 EiiLtlyptus trees m Australia. (After a drawing by Selleny.) 724 RESISTANCE OF FOLIAGE-STEMS TO STRAIN, PRESSURE, AND BENDING. RESISTANCE OF FOLIAGE-STEMS TO STRAIN, PRESSURE, AND BENDING. When the weight of the individual parts of these huge trees is considered, itis difficult to understand how their comparatively slender main stems are able tosupport a crown weighing many thousand kilogrammes, and how it is that theboughs extending far out from the trunk horizontally do not crack and breakunder the weight of the branches and leaves they carry. The culms of grassesand the stems of bushes and herbs are also so loaded as to astonish us. and wecannot help asking how it is they are able to keep erect, and how, when theirequilibrium is disturbed, they can resume their normal resting position almostat once. If we wish to investigate the mechanisms which make it possiblefor these plants to maintain
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1902
