462 EXPERIMENT STATION RECORD. 



active germination, wiiile still older seeds, incapable of germination even under the 

 most favoral)le conditions, manifested a still smaller blaze and finally gave such 

 weak currents that they could not be distinguished from the counter effect due to 

 polarization. 



Vitality of seeds, H. H. Dixox {Xature, 64 {1901), No. 1654, pi\256, «'57).— The 

 various experiments which have "been lately conducted to ascertain the effect of low 

 temperatures upon the vitality of seeds have led the author to investigate the effect 

 of high temperatures upon the vitality of- a large number of seeds. The author has 

 found that h\ drying seeds in an oven at 65 to 75° C. for a day, and then at 90° C. 

 for a day, a great many seeds will resist temperatures of 100° C, or even more. His 

 experiments were made with oats, rye grass, lettuce, sunflower, musk flower, alfalfa, 

 rape, California poppy, and poppy. Of these alfalfa proved the most resistant. 

 After an exposure of 1 hour to 110° C. and then 1 hour to 121° C, 10 per cent of the 

 seed germinated. Of other seeds investigated the maximum temperature was for 

 poppies 100° C. and Schizopetalon walkeri 105° C. The effect of exposure to the high 

 temperature was noticeable in all cases by the marked retardation of germination and 

 by the extremely slow growth afterwards. The young plants were weak and there 

 seemed to be a loss of sensibility to geotropic stimulus. Whether the plants would 

 become normal or not was impossible to say, as the conditions of the experiments 

 were such that they could not be grown to maturity. 



The author also reviews the experiments of Giglioli (E. S. R., 7, p. 406), in which 

 the action of both liquid and gaseous poisons to seeds was shown. In these experi- 

 ments prolonged action of oxygen, chlorin, nitric oxid, alcohol, and an alcoholic 

 solution of corrosive sublimate on seeds did not entirely destroy the power of germi- 

 nation. The author repeated a number of these experiments. Alfalfa seed exposed 

 from 10 to 30 days to the action of methyl alcohol, saturated solution of corrosive 

 sublimate and picric acid, did not have the powers of germination noticea])ly affected. 

 Seeds of different kinds of i)oppies resisted the action of alcohol but were killed by 

 corrosive sul^limate solution. An experiment by the author seems to show that 

 resistance to the poison is not due to a quiescent state of the i)rotoplasm of the seed, 

 but to the imperviousne.ss of the seed c<)at. A large number cd seeds of alfalfa were 

 selected, half of them punctured, all dried, and after drying immersed in the various 

 solutions mentioned ab(jve. The uninjured seeds were not affected by the poisonous 

 fluids, while the punctured ones had their vitality entirely destroye<l. 



The effect of hydrocyanic-acid gas upon grains and other seeds, C O. 

 TowNSEND {Maryland Sla.Biil. 75,p}t. lS3-19S,fi(js. 5). — This is the comi>leted ])aper, 

 a preliminary notice of which has already been given (E.S. R., 12, p. 959). The author 

 has investigated the effect of different strengths of hydrocyanic-acid gas upoiuthe 

 germination of dry and moist seeds, as well as the effect upon the edible ])roperties 

 of the same seeds when submitted for a considerable time to this gas. It was found 

 that dry seeds may be fumigated with the usual strength of hydrocyanic gas for the 

 length of time required for the destruction of animal life without in any degree 

 interfering with the germinative power of the seeds. Dry seeds may be subjected 

 to the influence of the gas for several months without entirely destroying the ability 

 of the seeds to germinate. When subjected to the influence of the gas derived from 

 1 gm. of potassium cyanid per cubic foot the seeds lose their germinating power at 

 the expiration of alxjut 8 months, while the same seeds subjected to the gas from 

 one-third the quantity of potassium cyanid will retain their vitality for at least 12 

 months. If exposed for from 15 to 60 days to the influence of hydrocyanic acid from 

 J to 1 gm. of potassium cyanid per cubic foot the germination of dried seeds is 

 accelerated, although the degree is not sufficient to be of any practical value. 

 Damp seeds are much more sensitive to the influence of gas than dry ones, and seeds 

 soaked for 24 hours or more will not germinate in gas stronger than 0.003 'gm. of 

 potassium cyanid per cubic foot. The seeds soaked for 24 hours and then left for 



