824 EXPERIMENT STATION EECOED. 



In conclusion the author states that although there appears to be good evi- 

 dence that hybridism has been an important cause of the multiplication of 

 species, there seems to be no logical support for the view that it has to do 

 with their actual origin. 



Some wild tuberiferous Solanums, L. Wittmack (Ber. Deut. Bot. Gescll., 

 SI {1913), Gen. Veisamml. Heft, pp. {10)-{34), figs. If). — Descriptions and illus- 

 trations are given of several specimens of Solanum sent to the author for 

 study following the appearance of his articles, formerly noted (E. S. R., 31, 

 p. 425), also a proposed systematic arrangement of several forms with refer- 

 ence to the views in this connection of several other authors. 



The relationship between the weig'ht of the seed planted and the charac- 

 teristics of the plant produced, II, J. A. Harris {Biometrika, 10 {1914), No. 

 1, pp. 72-84, fiffs. 4)- — III continuation of investigations previously reported 

 (E. S. R., 29, p. 522), the author reports on the constants measuring the influ- 

 ence of the weight of the seed planted upon the number of ovules formed and the 

 number of seeds developing in the pods of mature plants of Phaseolus vulgaris. 



There was found to be a sensible relationship between the weight of the 

 seed planted and the number of pods on the plant developing from it. There 

 was also a positive correlation between the weight of the seed planted and the 

 number of ovules and the number of seeds in the pods produced. The corre- 

 lations between weight and ovules and weight and seeds are said to be regarded 

 as the resultant of two other correlations, namely, that between the weight 

 of the seed planted and the number of pods per plant and that between the 

 number of pods on the plant and the characteristics of these pods. 



The conservation of vitality of seeds in soil periodically cultivated, O. 

 MuNERATi and T. V. Zappaeoli {Staz. Sper. Agr. Ital., 46 {1913), No. 5, pp. 

 347-371, fig. 1). — Experiments carried out with seeds of about 18 species of 

 common plants, buried at various depths up to 45 cm. in soil and examined at 

 varying intervals, are claimed to show that seeds of many cultivated or wild 

 plants having coverings more or less permeable by water show a power of con- 

 serving vitality when buried in soil that is in close relation to their germina- 

 bility at the time when they are planted. 



Effects of disinfectants on germinability of grain, A. Fbassi {Staz. Spei: 

 Agr. Ital., 46 {1913), No. 1, pp. 25-56). — Germination tests were riade with 

 wheat seed after exposure to the action of different disinfectants in solution 

 or in gaseous form during periods of varying length. The results given in con- 

 nection with each test show the various degrees of injury inflicted, which is 

 generally greater in case of moistened seeds than of those exposed only to 

 vapors, and still greater in case of seeds in solutions, length of time always 

 playing an important part. A bibliography is apiiended. 



Delayed germination in seed of Alisma plantago, W. Crocker and W. E. 

 Davis {Bat. Gaz., 58 {1914), No. 4, pp. 285-321, figs. 8).— A study is reported 

 of the delayed germination of the water plantain, which is said to be due to the 

 mechanical resistance of the seed coat. The seed coat was found to be com- 

 posed almost entirely of pectic substances, which acids and bases so weakened 

 that imbibitional and osmotic swelling of the embryo was capable of breaking 

 away the coat cap. The authors state that the seeds of Alisma, as well as water 

 plants in general, are capable of lying in water for years in an imbibed condi- 

 tion without losing their vitality. 



A bibliography is appended. 



Vegetation experiments on the evaporation of pine seedlings, A. Tol'skH 

 {Abs. in Zhur. Opytn. Agron. {Russ. Jour. Expt. Landw.), 13 {1912), No. 4, pp. 

 651, 652). — The author describes the method and gives the results of his inves- 

 tigations conducted during several years with reference to the amount of 



