. Plant anatomy from the standpoint of the development and functions of the tissues, and handbook of micro-technic. d is satisfactory. Do not allow the stone to gum up; keepplenty of oil upon it if it is an oil stone, or if a water stone keepit well lathered with soap and water, and wipe the stone cleanafter honing. Then strop the knife, drawing it over the leatherback foremost from heel to point (Fig. 145), reversing the facefor the back stroke, and keep this up until the knife readilyclips a hair. Cytological Methods.—Within comparatively recent timesmethods have been worked out whereby the
. Plant anatomy from the standpoint of the development and functions of the tissues, and handbook of micro-technic. d is satisfactory. Do not allow the stone to gum up; keepplenty of oil upon it if it is an oil stone, or if a water stone keepit well lathered with soap and water, and wipe the stone cleanafter honing. Then strop the knife, drawing it over the leatherback foremost from heel to point (Fig. 145), reversing the facefor the back stroke, and keep this up until the knife readilyclips a hair. Cytological Methods.—Within comparatively recent timesmethods have been worked out whereby the anatomy of cells17 258 PREPARATION OF SECTIONS and tissues can be laid bare in their finest details. These methodsare intended first of all to preserve the structure of the proto-plasts in its normal form, and then to cut a single cell into severalsections while keeping these in their natural sequence, andfinally to stain the sections so that different structures will takeon different colors. The preservation of the structure of the protoplasts is ac-complished by plunging the material into a solution, known. FIG. 145.—Illustrating how the section knife or razor is drawn across the strop. as the fixative, which instantly kills the protoplasts so that de-composition incident to slow dying is prevented, and then harden-ing the protoplasts by transferring the material to alcohol, be-ginning with weak alcohol and gradually increasing its strengthuntil absolute alcohol is reached, so as to avoid undue shrinkage. The material is next imbedded in paraffin, and sections ad-hering in ribbons are cut usually .005 mm. to .010 mm. thick,and these after mounting on a slide and being freed fromparaffin are stained with two or three different stains and thensealed in balsam in the form of permanent mounts. The processes thus briefly outlined will now be given indetail. The Fixing Process.—For the study of the finer structures THE FIXING PROCESS 259 of the protoplast Flemmings fixative h
Size: 2102px × 1189px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1900, bookcollection, bookdecade1910, bookyear1910
