BOTANY. 921 



without any nitrogen, and the third lot the same as the second with 

 the addition of an infusion of soil where peas had been grown. No. 1 

 grew well, No. 2 died of nitrogen starvation, and No. 3 grew well for 

 about 10 days, when the plants began to show appearances of nitrogen 

 starvation and no tubercles were visible. A few days later the plants 

 began to recuperate and the growth became normal and vigorous. On 

 the fifteenth day tubercles were abundant. 



[The author is in error in saving that the subject of nitrogen assimi- 

 lation has only been studied in connection with sterilized soil or sand, 

 as water cultures have been employed by Hellriegel, Hiltner, Frauk, 

 Lotsy, and others. — ed.] 



The tensile strength of cell walls, H. H. Dixon (Ann. Bot, 11 

 (1897), No. 40, pp. 585-588). — The author has conducted a series of ex- 

 periments to ascertain the coefficient of safety against osmotic pressure 

 in plant cells. From data collected from the breaking stress of fibers 

 of cotton and other plants and comparing the area of these fibers with 

 those of the cell walls of many plants he finds that every cell of the 

 leaf is able to sustain the high osmotic pressures which give rigidity to 

 the leaf and, so far as the strength of the cell walls is concerned, much 

 higher pressures might exist. 



On the composition of the membranes of some fungi, C. Tanret 

 (Bui. Soe. Ghim. Paris, 3. ser., 17 (1897) No. 20-21, pp. 921-927).— After 

 treating the mycelium of Aspergillus niger with water, alcohol, ether, 

 cold caustic; soda, and sulphuric acid, the author states that chitin is 

 present associated with a carbohydrate called fungose, which is similar 

 to, if not identical with that found in yeast, ergot, agarics, and boletus. 

 Having been found in such dissimilar fungi the author believes that 

 fungose is a constituent of the membranes of all fungi. 



The plants of saline soils, A. Feret {Monde des Plantes, 2. ser., 7 (1897), No. 96, 

 pp. 193-195). 



Plants and their environments, J. Costaxtix (Le vege'taux et les melieux cos- 

 miques. Paris: F. Alcan, 1898, pp. 296, figs. 296). 



A revision of the diagnosis of the species of Hymenomycetes, M. Britzel- 

 mayr (Bot. Centbl., 73 (1898), Nos. 5, pp. 129-135 ; 6, pp. 169-175). 



Critical studies of the North European forms of Agrostis, A. S. Murbkck 

 (Bot. Notiser, 1S98, No. 1, pp. 1-14). 



The effect of drought upon certain plants, Clara Cunningham (Proc. Indiana 

 Acad. Sci., lSDff, pp. 208-213, pis. ,?). — An experimental study was made on the effect 

 of drought on the different tissues of plants, the subject of the experiments being 

 oxalis, canna, corn, beans, castor beans, and cucumbers. 



Development of roots from cuttings, L. C. Corbett (West Virginia Sta. Bpt. 

 1896, pp. 196-199, pis. 3). — The author discusses the development of roots from 

 cuttings, and states tbat they do not have their origin in the callus, but grow from 

 the fundament formed in the tissue of a portion of the plant used as a cutting in a 

 similar manner to that of the development of new roots from the root or the plant 

 axis of a seedling. 



A device for measuring plant growth, L. C. Corbett ( West Virginia Sta. Bpt. 

 1896, pp. 236-240, pi. 1). — The author figures and describes a form of auxanometer 

 for which the advantage of a record made in ink in the form of a platted curve is 

 claimed. 



