1917] AGRICULTURAL BOTANY. 431 



Germination of seeds of Lepidium sativum in solutions of electrolytes, 

 P. Lesage {Conipt. Rend. Acad. Sci. [Pans^, 164 {1917), No. 2, pp. 119-121). — 

 Having observed in the work previously noted (E. S. R., 37, p. 26) that the 

 osmotic pressure of the solution in which seeds of L. sativum were being soaked 

 plays an important part in germination, and having entered upon a study of 

 the part played by dissociation in that connection, the author liere discusses 

 some of the mathematical and practical phases of that work. 



The influence of different media on the histology of roots, Sophie J. 

 WiLKiE (Trans, and Proc. Bot. Soc. Edinb., 27 (1915-16), pt. 1, pp. 76-78, pi. 

 1). — This is a short note on the differences found to exist in the anatomical 

 structure of roots of Monstera deliciosa grown in air, soil, water, wet gravel, 

 and damp soil. 



It was found that the development of the absorptive layer varies inversely, 

 and the mechanical tissue directly, with the humidity of the medium. There 

 is no variation in the size of the intercellular spaces of the fundamental tissue, 

 excepting the presence of lacuna? in the cortex of the water roots. 



The permeability of living cells to acids and alkalies, A. R. Haas (Jour. 

 Biol. Chem., 27 (1916), No. 1, pp. 225-232).— In view of the fact that meta- 

 bolism is strongly influenced by changing the chemical reaction of the proto- 

 plasm, the author has made a study of the penetration of the cell by reagents, 

 employing as indicators petals of Browallia speciosa and Pelargonium, the 

 perianth of the hyacinth, and the root of the red radish, which prove to be well 

 adapted to this purpose. Differences noted in the relative rate of penetration 

 by the hydrogen ion on employment of different methods are thought to be 

 explainable by the dissociation of the acids concerned. 



Salt antagonism in gelatin, W. O. Fenn (Proc. Nat. Acad. Sci., 2 (1916), 

 No. 9, pp. 534-538, figs. S). — Discussing previous contributions with explana- 

 tions regarding observed salt antagonisms, the author presents his own 

 hypothesis, which is said to be supported by experimentation on gelatin. This 

 is that anions antagonize cations in their effects upon organisms, the point of 

 maximum antagonism being an isoelectric point at which the amount of alcohol 

 needed for precipitation is at a minimum and the aggregation or amount of 

 precipitation at a maximum. 



Similarity in the behavior of protoplasm and gelatin, W. O. Fenn (Proc. 

 Nat. Acad. Sci., 2 (1916), No. 9, pp. 5S9-543, figs. 2).— Discussing the above and 

 other investigations, the author concludes that if we assume that the effect of 

 time in the Laminaria experiments of Osterhout (E. S. R., 32, p. 728) is to in- 

 crease the concentration of the salts in the cells of the tissue, a close analogy 

 to these experimental results is found in gelatin to which sodium hydroxid has 

 been added. 



Tolerance of fresh water by marine plants and its relation to adaptation, 

 W. J. V. Osterhout (Bot. Gaz., 63 (1917), No. 2, pp. 1 46-1 49) .—The author 

 has followed up studies previously noted (E. S. R., 30, p. 130) regarding the 

 effects of distilled water on protoplasm. He has found that remarkable differ- 

 ences exist between plants, and even between different cells of the same plant, 

 with respect to their tolerance of fresh water. These differences may prove to 

 be of significance in connection with adaptation. 



In case of Polysiphonia, many cells are killed by exposure to pure distilled 

 or fresh water for less than one minute. Instances are discussed of remarka- 

 ble tolerance by plants naturally, accidentally, or experimentally subjected to 

 great and quick alterations of salinity in the water. It is supposed that some 

 characters attributed to adaptation may have been present from the beginning 

 and that they may have been due originally to entirely different causes. The 

 fact that leaf cells, as compared with root cells of the same plant, withstand 



