How crops growA treatise on the chemical composition, structure, and life of the plant, for all students of agriculture .. . is probably of another kind. How diastase or other similar substances accomplish thechange in question is not certainly known. Soluble Starch.—^The conversion of starch into sugarand dextrin is thus in a sense explained. This is not, how-ever, the only change ofwhich starch is the bean, [Phaseolusmultiflorus), Sachs {Sitz-ungsberichte der WienerAkad., XXXVII, 57) in-forms us that the starch ofthe cotyledons is dissolved,passes into the seedling, andreappea
How crops growA treatise on the chemical composition, structure, and life of the plant, for all students of agriculture .. . is probably of another kind. How diastase or other similar substances accomplish thechange in question is not certainly known. Soluble Starch.—^The conversion of starch into sugarand dextrin is thus in a sense explained. This is not, how-ever, the only change ofwhich starch is the bean, [Phaseolusmultiflorus), Sachs {Sitz-ungsberichte der WienerAkad., XXXVII, 57) in-forms us that the starch ofthe cotyledons is dissolved,passes into the seedling, andreappears (in part, at least)as starch, -without conver-sion into dextrin or sugar,as these substances do notappear in the cotyledons during any period of germina-tion, except in small quantity near the joining of theseedling. Compare p. 64, Unorganized Starch. The same authority gives the following account ofthe microscopic changes observed in the starch-grainsthemselves, as they undergo solution. The starch-grainsof the bean have a narrow interior cavity, (as seen infig. 65, 1.) This at first becomes filled with a Fig. 65. GEEMINATIOir. 323 Next, the cavity appears enlarged (3,) its borders assumea corroded appearance (3, 4,) and frequently channels areseen extending to the surface (4, 5, 6.) Finally, thecavity becomes sq large, and the channels so extended,that the starch-grain falls to pieces (7, 8.) Solution con-tinues on the fragments until they have completely disap-peared. In this process it is most probable that the starchassumes the liquid form -without loss of its proper chemi-cal characters, though it ceases to strike a blue color withiodine.* Soluble AlbnminoidSi—As -we have seen (p. 104,) in-soluble animal fibrin and casein, by long keeping -withimperfect access of air, pass into soluble bodies, and lat-terly E. Mulder has sho-wn that diastase rapidly accom-plishes the same change. It would appear, in fact, thatthe conversion of a small quantity of any album
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectagricul, bookyear1868
