SEEIS WEEDS. 975 



torted and in many cases the shoot was unable to l)reak through the seed coats. In 

 other ca^es the peas failed entirely to germinate. If the seed was dried in contact 

 with the air or over concentrated sulphuric acid it was found that they would germi- 

 nate more promptly and the seedlings l)e more nearly normal. The experiments with 

 maize are described with considerable detail. Two rows of grain were detached 

 from the ear, the first coTisisting of 20 grains placed to germinate inunediately, while 

 the second was dried for 48 hours over concentrated sulphurii- acid, after which they 

 were placed to germinate. The first lot germinated 20 seed in 30 days, while the 

 second lot, which consisted of 19 seed, all germinated in 2 days. 



In the second experiment with maize 3 lots of seed were removed from the ear 

 while the grains were still in the milk stage. The first lot, consisting of 20 grains, 

 was placed to germinate immediately. The second was exposed for 8 days in the lab- 

 oratory, losing in this time a considerable portion of their water. The third lot was 

 dried for 8 days over a weak sulphuric acid, after which it was placed to germinate. 

 Of the first lot of seed but 2 germinated in 34 days, of the second lot 20 seed ger- 

 minated in 14 days, while of the third, which consisted of 15 grains, all germinated 

 in 3 days. 



The influence of formaldehyde on the germination of oats, F. Cranefield 

 {Wisconsin Sta. lipt. 190J, pp. ^68-272^. — In the previous report of the station an 

 account was given of the influence of formaldehyde on the germination of oats. In 

 the present report further studies are given showing the influence of this fungicide 

 on the viability of seed, in which stronger solutions were used and varying periods 

 of time employed. It was found that soaking the seed in a solution of 2J parts of 

 formaldehyde and 1,000 parts of water injured the seed oats from 6.4 to 17.4 per cent. 

 Where stronger solutions were used tlie injury was increased in direct proportion. 

 These tests were conducted under ordinary field conditions. In spite of the injury, 

 the successful use of this fungicide for the prevention of oat smut, the author believes, 

 warrants its continued use. 



The effect of depth of planting on the germination of clover seed, F. Crane- 

 field {Wiscons'ui tila. Rpt. 1902, pp. 27S-279, figs. 2). — The results of a number of 

 trials in planting clover seed at different depths are given, the germination of the 

 seed being noted at the end of 5, 10, and 20 day periods. The different lots of seed 

 were planted to depths of \ in., } in., J in., J in., 1 in., and 2 in. The experiments 

 described involved the planting of aliout 45,000 seed, and the results obtained show 

 that planting between \ and f in. ^\•as the most favorable for rapid germination and 

 produced the highest percentage of germination. When the seed were covered to a 

 depth of 1 in. less than half germinated and when covered with 2 in. of compacted 

 soil less than ^ germinated. 



The eflfect of sunlight upon the germinative power of seed, E. Laurent 

 {Compt. Rend. Acad. Sd. Paris, 135 {1902), No. 26, pp. 1295-1298) .—On accountof the 

 injurious action that sunlight is known to exert upon bacteria, yeasts, spores of cer- 

 tain fungi, etc., the author conducted experiments to ascertain its effect upon the 

 germinative ability of certain seeds. Seeds of wheat, rye, black and white mustard, 

 cress, clover, dandelion, Hieracium spp., sow thistle, and groundsel were placed in 

 tubes in series and exposed to the direct sunlight during a period of prolonged and 

 intense sunshine. They were afterwards placed to germinate, and it was shown that 

 the sunlight had exerted a detrimental effect upon them which in some cases entirely 

 destroyed the embryos of the seed. In general, the larger seeds, such as rye, wheat, 

 and those having white seed coats, as the white mustard, were less injured by the 

 solar radiation than the small seed or those provided with dark-colored seed coats. 



Experiments on the germination of seed preserved in a vacuum, E. Laurent 

 {Compt. Rend. Acad. Sci. Paris, 135 {1902), No. 24, pp. 1091-1094).— Iri 1894 the 

 author placed the seeds of a large number of field and garden plants of the crops of 

 1892, 1893, and 1894 in test tubes, and so arranged them as to permit of the liberation 



