AGRICULTURAL BOTANY. 127 



favor germinntion. Xylol (1 cc. per liter) favors both the germinating power 

 of the seed and the saccharifying power of the enzyni. Ammonium chlorid 

 increases the li(inefying power of the enzym, and lactic acid, vegetable ])eptone, 

 and calcium liyixx-lilorite favor germination and also diastatic action. 



The osmotic strength of cell sap in plants growing under different condi- 

 tions, K. Dkaishi.e and IIii.d.v Lake (Xcir I'liiiloL. '/ (i.'>0.7), .Vo. 8. pp. 1SD- 

 JUl). — It is claimed that comparatively few oI)scrvations on the osmotic strength 

 of cell sap in i)lants growing under different physical conditions have been made, 

 and the authors have undertaken a series of experiments to determine this 

 factor. 



Tlie method ilcviscd involves the observation of tiie plasmolysis of the cells, 

 and by this means a numlu'r of plants were examined with regard to the 

 strength of their cell sap. A series of sodium-chlorid solutions was made up 

 in various gram-molecule concentrations. Portions of the plant the strength 

 of whose cell sap was to l)e deternnned were placed in water. Strips of the 

 epidermis of the leaf were placed in a drop of the solution and gently covered 

 with a cover ghiss, and when the solution just failed to plasmolyse it was taken 

 as isotonic with the cell sap. It was found most convenient to use plants with 

 red coloring matter in the epidermis, and liut little difference was noticed in 

 the strength of sap I)etween the cells containing the red and those containing the 

 colorless materials in the same leaf. 



The data presented show that there was a greater concentration of cell sap 

 in those plants which had been most strongly subjected to factors tending to 

 promote a loss of water by transpiration. In considering the effect of the con- 

 centration of the cell sap on the absorption of water, it is shown that the con- 

 centration exerts an important physiological bearing on the plants. From 

 observations made on plants growing in mountain regions and other dry situa- 

 tions it is determined that a high osmotic strength of cell sap may prove a 

 valuable ]iiiysiologic-;il chnracter in connection with water alisorption. 



On the sensibility of chlorophyll in tolerant and intolerant species of 

 plants, W. LuBiMENKO (Coinpt. Tlciul. Acad. .S'c/. [Pari.^], JJ/l (190')). No. IS, 

 /)/'. •J-^-Ji, o36). — In continuation of previous observations (E. S. R.. 17, p. 0.51), 

 the author made comparative studies of the carbou-dioxid assimilation of plants 

 tolerant and intolerant to light. 



For the intolerant species he selected Scotch pine, European larch, white 

 birch, and the common locust, while for the shade-growing species fir, yew, 

 linden, and beech were chosen. For each of these species 2 series of experi- 

 ments were carried on, one in artificial feeble light, the other in full sunlight. 

 Spectroscopic studies were made of the chlorophyll solutions of the different 

 species. 



It is claimed that the assimilative energy depends on the concentration of 

 the coloring matter in the chloroplast. The curve which represents the assimi- 

 lative energy following the concentration of the coloring matter reaches its 

 highest limit under natural radiation for the intolerant species and falls below 

 that limit with the tolerant ones. The author raises the question as to whether 

 among tolerant and intolerant plants the physical difference in concrentratiou 

 of chloi'ophyll is not possibly due to difference in physiological irritability 

 of i)rotoi)lasm when exposed to light. 



The growth of chlorophyll-bearing plants in confined atmospheres in the 

 presence of organic materials, Moi.i.iakd {C'liiipt. Reml. AnnL Sci. ll'dris], 

 I'll (lOO-')). \o. 7. pp. 3S:)-.ini). — A report is given of investigations with rad- 

 ishes growH in fermentation tubes in the jiresence of various forms of starch, 

 sugar, etc., which show that the plants were able to make considerable growth. 



