Digestion Clears the View.--Good digestion makes for clearer vision in the microscope, plant scientists of the U. S. Department of Agriculture have discovered. The digestion, in this case, is of the object to be examined undet high magnification.
Searching for fundamental facts of heredity, scientists need to know more about the interior of cells, and particularly about the appearance and arrangement of the chromosomes that are believed to control the hereditary behavior of the plant. Minute as single cells are, the scientists have devised ways of making microscope slides that expose cells in single layers and so enable the observer to study single cells. But the cell walls are not clearly transparent and interfere with views of the cell interiors.
S. L. Emsweller and Neil Stuart of the Agricultural Research Administration, trying to reduce this interference, applied Solvents and caustic chemicals to dissolve or eat away part of the cell walls. Failing with these, they turned to organic preparations and have had better success. An enzyme preparation literally digests away part of the cell wall and in some way affects the internal structure, causing chromosomes to spread out readily. The microscope slides of "digested" cells give clearer views of the chromosomes.
They have also had promising results with substances prepared from fungi that have been studied in wartime research on decay and destruction of fabrics such as tents, uniforms and sandbags. Carefully controlled, the substances that break down the fibers of a sandbag can also be used to break down part-and only part--of the wall of a plant cell.
Early experiments have been mainly with pollen cells. Results with cells from roots have been less satisfactory. Other enzymes and digestive sub: stances will be tested with root cells in developing the new and promising tool for plant research.
R. H. O.