. An introduction to vegetable physiology. Plant physiology. 140 VEGETABLE PHYSIOLOGY bacteria, one of which forms nitrites from the ammonia compound, and the other transforms nitrites into nitrates. Certain fungi differ in their behaviour from green plants, absorbing ammonia compounds without such conversion. It is in the way described that a normal green plant absorbs all the nitrogen which it uses for the construction of food substances. The nitrogen of the air is utilised only by its being made to enter into some form of combination by bacteria in the soil. There is much greater activity i
. An introduction to vegetable physiology. Plant physiology. 140 VEGETABLE PHYSIOLOGY bacteria, one of which forms nitrites from the ammonia compound, and the other transforms nitrites into nitrates. Certain fungi differ in their behaviour from green plants, absorbing ammonia compounds without such conversion. It is in the way described that a normal green plant absorbs all the nitrogen which it uses for the construction of food substances. The nitrogen of the air is utilised only by its being made to enter into some form of combination by bacteria in the soil. There is much greater activity in this fixation than was thought till re- cently, very considerable amounts of atmospheric nitrogen being made available for absorption by this instrumentality. Certain lowly Algae are said to have the power of using it, but the process is not fully understood. A few green plants can also use atmo- spheric nitrogen, but their power depends upon the association with their roots of certain fungi or bacteria which infest the cortical tissues and generally develop peculiar tubercular structures upon the roots (fig. 82). The power was first observed among the members of the Natural Order Leguminosce, but it has since been found to be possessed by plants of other families and seems to be more widespread than was at first imagined. The actual mode of absorption in these cases also is obscure ; the parts played by the root and the fungus or bacterium respectively are not at all determined. The atmospheric nitrogen apparently is made. Fio. 82 Root or a Legomi- K0D3 PLAHT, SHOWIKO THE Tttbeeoles attached to the Main Root and to its 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 Green, J. Reynolds (Joseph Reynolds), 1848-1914. London, J. & A. Churchill
Size: 959px × 2606px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondonjachurchill
