Our knowledge of the root systems of grasses falls far short of that of their visible parts—not because there is less to know, but because it is so troublesome to get at facts when they are hidden under layers of earth. There is no short cut to this knowledge; merely uprooting the plants is of little use, for it partially destroys some of the underground organs and displaces the rest. An American botanist, J. E. Weaver, however, has worked out a laborious and thorough technique, by the aid of which he has arrived at a much clearer picture of root systems than had been obtained before. The method he employed was to dig a trench by the side of the plant to be examined, about 5 ft. in depth and of convenient width. This afforded an open face which could be explored with a hand-pick. The original trench often had to be deepened to 8 or 10 ft. and sometimes more. To ensure certainty as to the maximum depth of the root endings, the soil was usually undercut for about a foot below the deepest of them, and was carefully examined as it was removed. It was found that when the root system thus exposed was photographed, many of the finer branches and root ends were always obscured; experience showed that a more accurate record of the extent, position and minute branching of the root system could be obtained by means of a drawing to scale on a large sheet of squared paper.