210 PHYSIOLOGY [BoT. Absts., Vol. VIII, 



PROTOPLASM, MOTILITY 



1450. Anonymous. The components and colloidal behavior of protoplasm. Sci. Amer. 

 Monthly 2 : 271-272. 1920. [From Science 51 : 595-596. 1920.] 



DIFFUSION, PERMEABILITY 



1451. Knight, R. C. Plant physiology. Sci. Prog. [London] 15:200-206. 1920.— This 

 is a brief review of some important papers dealing with storage and translocation of the food 

 products in plants. — /. L. Weimer. 



1452. Mann, H. An apparatus for continuous dialysis or extraction. Jour. Biol. Chem. 

 44:207-209. 1920. 



1453. Mtjkerji, J. N. The excretion of toxins from the roots of plants. Agric. Jour. 

 India 15: 502-507. 1920. — The conclusions of Fletcher (Mem. Dept. Agric. India, Bot. Ser. 

 2': 1-16. 1908) that plants secrete toxic substances are held to be due to the use in his 

 experiments of too concentrated a solution. Data of experiments with Knop's nutrient 

 solution having a total salt concentration of 0.11 per cent are presented, where wheat, 

 cajanus, and grain were grown. The solution which had previously grown a set of plants 

 supported better growth than did the fresh solution. — /. /. Skinner. 



1454. Shull, C. a. Absorption limits. [Rev. of: Harvey, R. B., and R. H. True. 

 Root absorption from solutions at minimtmi concentrations. Amer. Jour. Bot. 5:516-521. 

 1918 (see Bot. Absts. 2, Entry 547).] Bot. Gaz. 68: 486. 1919. 



v/ater relations 



1455. Langdon, LaDema M. Wood structure and conductivity. [Rev. of: (l) Farmer, 

 J. B. On the quantitative differences in the water-conductivity of the wood in trees and shrubs. 

 Proc. Roy. Soc. London B 90: 218-250. 1918 (see Bot. Absts. 2, Entries 305, 306; 4, Entry 

 1413). (2) Holmes, M. G. Observations on the anatomy of ash-wood with reference to 

 water-conductivity. Ann. Botany 33: 255-264. 7 fig. 1919 (see Bot. Absts. 3, Entry 1109).] 

 Bot. Gaz. 68: 483-^84. 1919. 



MINERAL NUTRIENTS 



1456. MoLLiARD, M. Action des acids sur la composition des cendres du Sterigmato- 

 cystis nigra. [Action of acids on the composition of the ash of Sterigmatocystis nigra.] Compt. 

 Rend. Acad. Sci. Paris 169 : 990-993. 1919. — The author has previously demonstrated that the 

 accumulation of ash in Sterigmatocystis nigra is much less when ammonium chloride replaces 

 ammonium tartrate as the source of nitrogen. In both cases the acidity increased during the 

 first period of growth, but when the sugar of the culture medium disappears, acidity decreases 

 when ammonium is used, because of the utilization of the latter. On the other hand, the 

 use of ammonium chloride results in the accumulation of hydrochloric acid, which is not 

 utilized by the fungus. During the first 2 days the amount of mineral utilized by the fungus 

 is more than doubled when ammonium tartrate is used as a source of nitrogen. The author 

 regards this result as due to the effect of hydrochloric acid on the permeability of the fungal 

 cells. By means of analyses of the ash of fungi grown with ammonium tartrate and ammo- 

 nium chloride as sources of nitrogen, the author finds that the mycelium of Sterigmatocystis 

 grown on the ammonium tartrate solution contains ash in about the proportions found in 

 the storage organs of higher plants. Only a small part of the sulphur and magnesium of the 

 culture medium was absorbed, but all the phosphorus and potassium of the solution was 

 recovered from the mycelium. The ash of the fungus grown on the ammonimn chloride 

 medium was found to contain reduced amounts of sulphur, potassium, and especially mag- 

 nesium. The author finds that the presence of hydrochloric acid in the medium reduces 

 the permeability of the plasma membrane in an unequal fashion, the permeability to some 

 substances being notably reduced. Attention is also called to the fact that the morphological 



