. Foundations of botany. Botany; Botany. 262 FOUNDATIONS OF BOTANY prepared cross-sections through the sorus are available, especially il the material is fresh. Examine the spores and note the sha,pe, color, and surface. If the spores are shrunken, a drop of potash solution will restore the natural plumpi),ess. Draw. Spore-measurements are important in determining species. The uredospores of Puccinia graminis may be distinguished from those of other species common ^ on grasses by the greater proportionate length. The structure of the black spores (teleutospores) can be made out with- out diffi
. Foundations of botany. Botany; Botany. 262 FOUNDATIONS OF BOTANY prepared cross-sections through the sorus are available, especially il the material is fresh. Examine the spores and note the sha,pe, color, and surface. If the spores are shrunken, a drop of potash solution will restore the natural plumpi),ess. Draw. Spore-measurements are important in determining species. The uredospores of Puccinia graminis may be distinguished from those of other species common ^ on grasses by the greater proportionate length. The structure of the black spores (teleutospores) can be made out with- out difficulty. Some should be found attached at the base. Note the parts and the difEerences in color in different portions. Make careful drawings to show shape and structure of both kinds of spores. Boil a portion of a rust-injured plant in potash solution, pick it to pieces on a slide under the magnifier or dissect- ing microscope, use a cover-glass and examine the preparation for mycelium, using a high power. 313. Cultivation on a Host-Plant. — If practicable, find some wheat or gi-ass which has remained over winter with the black rust upon it. Tie a bunch of this to a barberry bush while the leaves are young or unexpanded. When the time arrives for the appearance of the cluster-cups, note whether they are any more abundant on this bush than,on others. Are you sm-e that the rust you have is the one to which the barberry cluster-cups belong?. Pig. 193. —a Group of Spores of Wheat Bust {Puccinia graminis). (x about 440.) M, u, uredospores; t, a teleu- 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 Bergen, Joseph Y. (Joseph Young), 1851-1917; Eastwood, Alice, 1859-1953. Boston, Ginn & Co.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
