126 EXPERIMENT STATION EECOKD. 



with a normal nutrieut solution to which were added various compounds of 

 calcium, potassium, sodium, and magnesium, comparisons being niii.de between 

 each individual salt. The solutions were made isotonic, while in another series 

 the strength of the solutions was raised to the same degree of isoconcentration. 



The author found that when isotonic solutions were used the plants resembled 

 one another in external appearance, in the amount of dry matter, and in ana- 

 tomical characters, as well as in the percentage of nitrogen they contained. 

 When, on the other hand, the plants were grown in isoconcentrated solutions, 

 especially in the case of such salts as magnesium sulphate and sodium chlorid, 

 the plants differed not only in their nitrogen content but in other respects. 



In 1905 sugar beets were grown in soil cultures in which the osmotic pressure 

 of the soil solutions was raised either by lowering the amount of water in the 

 vessels or by introducing corresponding amounts of sodium chlorid. In both 

 cases the beets had the same sugar content, from which the conclusion is 

 drawn that by making use of the osmotic pressure of the nutrient solutions, 

 other conditions being equal, it is possible to regulate not only the total yield 

 of di-y matter, but, within certain degrees, its chemical composition. 



In 1907 experiments were made with oats and millet, from which it is con- 

 cluded that (1) when the amounts of water are equal and the concentrations 

 and the amounts of nutrient substances differ the assimilative activity of the 

 leaves increases with the increase of concentration, (2) when the concentrations 

 are equal the assimilative activity of the leaf increases with the amount of 

 water and the nutrient substances, and (3) when the amount of nutrient salts 

 is equal and the water and concentrations differ the assimilative activity of the 

 leaf diminishes. 



The influence of sugar solutions of different degrees of concentration on 

 the respiration, turg'escence, and growth of cells, A. Maige and G. Nicolas 

 {Ann. Sci. Nat. Bot., 9. sen, 12 {1910), No. 2-6, pp. 315-368).— A study is re- 

 ported on the effect of different dilutions of saccharose, maltose, lactose, glucose, 

 and levulose on the respiration, turgescence, and growth of bean seedlings. The 

 beans were sprouted and in an etiolated condition were transferred to solutions 

 of the different sugars and the carbon dioxid, oxygen, and respiratory coeffi- 

 cients determined. 



The sugar solutions were found to have an osmotic and plasmolytic effect, 

 retarding growth, or to penetrate and diffuse in the cell. The penetrating power 

 was found to vary with the different sugars, and the osmotic action of solutions 

 of equal concentration varied with their penetrating power. All sugar solutions 

 were found to modify respiration after penetrating the cells. The influence of 

 a given sugar on a plant will depend on its penetrating power, its osmotic 

 activity, and its specific action on the chemism of respiration. Sugars of the 

 same group differ little in their specific action, and for equal concentrations their 

 activity is in direct relation to their penetration, saccharose being more active 

 than maltose, and maltose more so than lactose, glucose, and levulose. 



The absorption of nutritive substances from the soil by the sunflower in 

 connection with the formation of organic matter, I. Konovalov {Separate 

 from Izv. Kiev. PoUteJch. Inst., 1909, pp. 143; abs. in Zliur. Opytn. Agron. {Russ. 

 Jour. Expt. Landtv.), 11 {1910), No. 2, pp. 266-268).— Aftev a review of the 

 literature relating to the absorption of mineral salts and the increase in organic 

 matter in various plants under cultivation, a description is given of experi- 

 ments with several varieties of sunflowers, in which the dry matter was deter- 

 mined at intervals of from 5 to 8 days from the time of the sprouting of 

 the seed to the ripening of the plant. 



In all the varieties the process of increase of organic matter proceeded 

 approximately in like manner. When the flowering heads were being formed, 



