. Plant studies; an elementary botany. Botany. ROOTS 91 absorb moisture from them. By these root liairs the aljsorb- ing surface, and hence the amount of al)sor}(tion, is greatly increased. Individual root hairs do not last very long, but new ones are constantly ap- jiearing just behind the advancing root tips, and the old ones are as constantly disap- pearing. (1) Geofrojjism and liydrotrojiisiii. — ^lany outside influences affect roots in the direction of tiicir growth, and as soil roots are espe- cially favorable for ob- serving these influ- ences, two prominent ones may be mentioned. The i
. Plant studies; an elementary botany. Botany. ROOTS 91 absorb moisture from them. By these root liairs the aljsorb- ing surface, and hence the amount of al)sor}(tion, is greatly increased. Individual root hairs do not last very long, but new ones are constantly ap- jiearing just behind the advancing root tips, and the old ones are as constantly disap- pearing. (1) Geofrojjism and liydrotrojiisiii. — ^lany outside influences affect roots in the direction of tiicir growth, and as soil roots are espe- cially favorable for ob- serving these influ- ences, two prominent ones may be mentioned. The influence of gravity, or the earth influence, is very strong in directing the soil Fif:. S"). Appurntns to stiow tlio ri-*priiis;f to \\at(T {h3-drotro})isni) upon the part of roots. The ends {«) of the box ha^'e hooks for hanging, while the box proper is a cylinder or trough of wire netting and is filled with damp 8a\vdust. In the sawdust are planted peas {g), whose roots (/;, i, t, in) first descend until they emerge from the damp sawdust, but soon turn back to\vard it.—After 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 Coulter, John Merle, 1851-1928. New York, D. Appleton and Company
Size: 1847px × 1352px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1900
