Contributions in geographical exploration . frequent floods coming down throughout thesummer might be expected to scatter this vegetation far andwide over the everchanging ash and pumice bars of the lowerKatmai Valley. Just below the junction of Martin Creekwith Katmai River lies an extensive flat covered by river •220 The Ohio Journal of Science [Vol. XIX, No. 4, borne wash of ash, pumice, and black sand. The latter comesfrom the glaciation of the volcanic slopes of Martin and Mageik,and with the great flood of 1915 became mixed in all proportionswith the ash and pumice of the upper Katmai, a
Contributions in geographical exploration . frequent floods coming down throughout thesummer might be expected to scatter this vegetation far andwide over the everchanging ash and pumice bars of the lowerKatmai Valley. Just below the junction of Martin Creekwith Katmai River lies an extensive flat covered by river •220 The Ohio Journal of Science [Vol. XIX, No. 4, borne wash of ash, pumice, and black sand. The latter comesfrom the glaciation of the volcanic slopes of Martin and Mageik,and with the great flood of 1915 became mixed in all proportionswith the ash and pumice of the upper Katmai, and spread alongthe western side of the river valley. Towards the river the blacksand content gradually diminishes until the soil becomesa pure mixture of ash and pumice. The loose texture of thisriver deposited material was in striking contrast to the finelydivided, compact ash of the lower stretches, and offered a soilwhere physical conditions appeared ideal for the growth ofseedling plants. Nevertheless the only plant taking advantage. Photograph by R. F. GriggsA LUPINE GROWING ON THE ASH the soil is almost devoid of nitrogenous compounds as shown by theanalysis, the lupines thrive and produce seed in abundance. of these conditions was a legume, Liipinus nootkatensls. Theseplants were quite numerous and apparently were normaland healthy, having produced an abundance of ripened seedby the middle of August. Those growing farthest out on theash were somewhat stunted in growth, but this was not to bewondered at considering that they had to withstand the buffet-ings of many a fierce sandstorm in which their lower leaveswere cut to pieces by the sharp wind-driven volcanic ash. Allof the lupines examined had an abundance of nodules on theirroots. These must have been the source of their nitrogen for Feb., 1911)] Nitrogen Content oj Volcanic Ash 221 there was nothing Hke sufficient total nitrogen, much less watersoluble nitrogen, present in the ash for the sustenance
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