332 EXPERIMENT STATION RECOED. 



The failure of plants grown in window boxes to develop fleshy roots is at- 

 tributed to the abnormal elongation of the hypocotyl, and it was found that 

 when the hypocotyl elongates to twice or more its normal length all power of 

 transforming into a thickened root is lost. 



Observations made on a number of other root crops show that the same 

 phenomenon is possessed by them as the radish. 



Tuber formation by potato, G. Bauer (Natur, 17 (1912), p. 363, fig. 1; al)S. 

 in Bot. CentU., 123 (1913), No, 9, pp. 218, 219).— A potato plant grown in good 

 soil in a flower pot and covered with a dark pasteboard cylinder during most 

 of the early and all of the latter portion of its growth, w^as found in September 

 to have well developed tubers and to bear normal leaves on the part grown in 

 exposure to light. 



The effects of assimilation in cultivated plants, S. Steakosch (IY. Conf. 

 Internat: Gen^tique Paris, Compt. Rend, et Raps., 1911, pp. 275-277). — The 

 author has attempted to estimate the value of the materials taken from the soil 

 by various cultivated plants. The estimation of the nutrients consumed by the 

 plant is made from a chemical analysis of the entire plant, and the value of 

 the produce is calculated according to the physiological values of the utilizable 

 substances harvested. Taking the value of the elements absorbed from the soil 

 as 1, the different crops reported ranged from 1.6 to 24.75. Oats are given at 

 S.25; wheat, 4; barley, 4.5; potato, 5.5; sugar beets, 9.3; alfalfa, 12.75; and 

 sainfoin, 20.75. 



Alternations of humidity and dryness as affecting germination of seeds 

 of some weeds, O. Munerati and T. V. Zapparoli (Staz. 8 per. Agr. Ital., Jf6 

 (1913), No. 3, pp. 157-195). — Pursuant to work previously reported (E. S. R., 

 28, p. 427), the author gives tabular details of studies, on about 30 kinds of 

 seeds, carried out under controlled conditions from the summer or fall of 1910 

 through May of 1912. 



It is stated that among the plants which germinate slowly and partially when 

 kept in a constantly moist medium, but quickly and in high percentages when 

 brought into a humid atmosphere after long dryness, are Avena fatua, Qalium 

 aparine, Papaver rhceas, Plantago lanceolata, and Amarantus retroflexus. 

 Among those which germinate in low percentages in alternating humidity and 

 dryness are Rapistruni rugosum, Myagrum perfoliatum, Sinapis arvenis. Salvia 

 pratensis, Almtilon avicennce, Setaria italica, and CEJnothera 'biennis. Among 

 those which may long retain vitality without germination in a medium alternat- 

 ing between humidity and dryness are Convolvulus sepium, Lappa major, 

 Sorghum halepense, and Solanum nigrum. Among those apparently but little 

 affected by A-ariations of humidity are Vicia segetalis, V. cracca, V. hirta, 

 Lathyrus aphaca, Cirsium arvense, Eruca sativa, Daucus carota, and Cuscuta 

 epithymum. Panicum crus-galli and Rumex crispus are among those which, 

 while germinating more or less in any sort of alternations of humidity and dry- 

 ness, do not germinate in continuous humidity but are able to retain long their 

 vitality. 



Influence of manganese sulphate on germination, J. Crochetelle (Jour. 

 Agr. Prat., n. sen, 26 (1913), No. 39, pp. 898, 55P).— Reporting results of ex- 

 periments carried out with seeds of several common plants subjected to the 

 action of manganese sulphate in different strengths, the author states that the 

 species tested behaved very differently at different concentrations. The germina- 

 tion of clover fell off very rapidly at concentrations above 1 per cent, the cereals 

 appearing more indifferent to an increase of concentration. In limy clay soil' 2 

 concentrations favorable to germination were found, one about 0.1 to 0.2 per 

 cent, the other about 0.8 to 1 per cent. 



