SEEDS WEEDS. 987 



a compressed air refrij-eratof to temperatures raugiug from — 'M.IS C. 

 to — 5o.89° C. — an a\era{ie teinperature of — 11.93'^ ('. The seeds were 

 exposed for a total of J 18 days. After each refrigeratiou the tempera- 

 ture slowly rose to that of the interior of the receiver, while the refrig- 

 erations took place rapidly. Upon the conclusion of the cxpeiiment 

 the seeds were taken out and planted. The wheat, oats, and fennel 

 came up promi)tly. Out of 00 seeds of the sensitive plant only 1.} 

 germinated. Of the lobelia seed, which, on account of their small 

 uess, were not counted, only 10 sprouted. The check lots of the seed 

 showed that the failure of the sensitive plant seed to germinate could 

 not be attributed to the cold; but the lobelia seed were certainly killed 

 by the low temperatures. The author thinks it is probable that seeds 

 can remain uninjured in a medium unsuited for respiration, ])royided 

 there is nothing to injure their protoplasm through chemical action. 



Additional tests of garden seeds, L. F. Kinney and G. E. Adams 

 {Rhode Island Sta. Irul. 43, pp. 13). — This is in continuation of work 

 published in Bulletin 3r) of the station {¥j. S. R., 8, p. 233). One hun- 

 dred and fifty-one samples of vegetable seeds were collected and tested. 

 The vitality of 34 of the samples fell below 50 per cent. Twenty-three 

 lots of the same variety of seeds were tested in 1895 and 1890, and in 

 10 lots the germination in 1890 was considerably lower than that of the 

 previous year. The authors think from results of their investigations 

 that it is evident that old seed were mixed with the sanqdes obtained 

 both years. 



Duplicate tests were made of GO samples in which the germinations 

 are reported upon at length. These tests showed in 8 samples the same 

 percentage of germination in both cases. In 10 sami)les the second test 

 showed 1 ijer cent lower germination; in 4 samples, 2 per cent lower; 

 in 5, 3 per cent lower; and in 3, 4 per cent lower, or a variation of less 

 than 5 per cent in the 2 tests. 



The hawkweed, L. II. Jones ( Vermont ISta. Rpt. 1895, pp. 115). — 

 Brief notes are given on the occurrence of the hawkweed {Hieracium 

 aurantiacum), wduch threatens to become one of the most troublesome 

 weed pests in the State. Experiments have been conducted to ascer- 

 tain the best means of killing the weed in grass lands, and it was found 

 that it may be completely exterminated in less than a year by plowing, 

 followed by clean culture, so as to allow no growth of the jilant above 

 ground; and that salt applied to the plants kills them very (juickly, the 

 amount necessary not being sullicient to injure the grass mateiially. 

 Where a large area of grass land is to be cleared of the weed, it is 

 l)robable that the application of a cheap grade of salt at the rate of 

 about 1 or 2 tons per acre would prove profitable; the land afterwards 

 to be plowed and followed by clean cultivation. 



The orange ha-wkweed, L. K. -Ionks and W. A. Orton ( Wrmout 

 Sta. iinl. 50, pp. 15, Ji(/s. 5). — This bulletin gives a more extended 

 account of the orange hawkweed {Hieracium aurantiacum) thijn that 

 included in the Annual lleport of the station for 1895 (E. S. K., 8, 



