. Elements of botany. Plants. 222 ELEMENTS OF BOTANY. free. It may be found flourishing in unfrozen springs, even in mid- winter. 271. Examination with the Magnifying Glass^ — Float a little of the material in a white plate, using just water enough to cover the bottom of the latter. Study with the magnifying glass and note the green color of the threads and their great length as compared with their thickness. Are all the filaments about equal to each other in diameter ? Handle a mass of the material and describe how it feels between the fingers. 272. Examination icith the Microscope. — Mount i
. Elements of botany. Plants. 222 ELEMENTS OF BOTANY. free. It may be found flourishing in unfrozen springs, even in mid- winter. 271. Examination with the Magnifying Glass^ — Float a little of the material in a white plate, using just water enough to cover the bottom of the latter. Study with the magnifying glass and note the green color of the threads and their great length as compared with their thickness. Are all the filaments about equal to each other in diameter ? Handle a mass of the material and describe how it feels between the fingers. 272. Examination icith the Microscope. — Mount in water under a large cover-glass and examine first with a power of about 100 diameters, then with a power of 200 diameters or more. Note the struc- ture of the filaments, each made up of a row of cells placed end to end. Move the slide so as to trace the whole length of several filaments, and, if the unbroken end of one can be found, study and sketch it. Study with the higher power a smgle cell of one of the larger filaments and make out the details of structure shown in Fig. 192. Try to ascertain, by focusing, the exact shape of the cell. Count the bands of chlorophyll. The number of bands is an important character in distinguishing one species from another. Eun in five-per-cent salt solution at one edge of the cover-glass (withdrawing water from the other band containing edge with a bit ). If any change chlorophyll;;;, in the appearance of the cell becomes evident, make Pl/renoids, little ^ gketch to show it. What has happened to the cell- contents ? Explain, by reference to what you know of osmose, the cause of the change. On a freshly mounted slide run in iodine solu- tion, a little at a time, and note its action on the nucleus. Is any starch shown to be present ? If so, just how is it distributed through the cell ? 273. Reproduction of Spirogyra. — The reproductive process in Spirogyra is of two kinds, the simplest being a process of fission, not un
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
