More than 20 years ago machines were devised by Kuntze, Michalowski (27, p. 86), Huss (15), and later by Hughes (14), to scarify impermeable seeds. Other methods have been recommended and employed to some extent for hastening the germination of seeds. Hiltner (13, p. 44) treated seeds of red clover, white clover, and alfalfa 10, 30, and 60 minutes with concentrated sulphuric acid and found that the best germination resulted from the 60-minute treatment. Love and Leighty (21) also treated the seeds of various legumes with concentrated sulphuric acid and obtained a better germination in all cases. In their investigations with _Melilotus alba_ it was found that a 2-hour treatment resulted in some injury to the seed, but that a treatment varying from 25 minutes to 1 hour gave good results. In most cases in our investigations the seed coats of sweet clover became permeable to water after a treatment of 15 minutes in concentrated sulphuric acid, and within 5 minutes all of the Malpighian cells were destroyed down to the light line. Harrington (10) found that the soil, season, climate, color, or size of red-clover seeds had no influence upon the percentage of impermeable seeds and that the good germination ordinarily obtained with red clover was due to the scarifying of the seed coats by the rasps of hulling machines. Harrington (11) also studied the agricultural value of impermeable seeds and found that alternations of temperature cause the softening and germinating of many impermeable clover seeds when a temperature of 10° C. or cooler is used in alternation with a temperature of 20° C. or warmer and that the effect of such an alternation of temperature is greatly increased by previously exposing the seeds to germinating conditions at a temperature of 10° C. or cooler and is decreased by previously exposing the seeds to germinating conditions at a temperature of 30° C. It is a well-known fact that impermeable seeds which remain in the field over winter germinate readily the following spring. The light line is the most important and interesting feature of the Malpighian cell, at least so far as _Melilotus alba_ and _M. officinalis_ are concerned. But one light line occurs in the Malpighian cells in most Leguminosæ, although Pammel (32) reports two well-developed light lines in _Gymnocladus canadensis_, Junowicz (16) found three in _Lupinus varius_, and Sempolowski (36) two in _Lupinus angustifolius_.