118 PHYSIOLOGY [Box. Absts., Vol. X, 



WATER RELATIONS 



751. Miller, Edwin C. Water relations of corn and the sorghums. Trans. Kansas 

 Acad. Sci. 29: 138-141. 1920. — Sorghum, having only about | the leaf surface of corn and a 

 root system approximately twice as great, is able to absorb water from the soil as fast as evap- 

 oration from the leaves necessitates replacement. It therefore has an advantage over corn 

 under climatic conditions conducive to great water loss. "The sorghums can produce more 

 dry matter for each unit of leaf area under severe climatic conditions than the corn plant." — 

 F. C. Gates. 



MINERAL NUTRIENTS 



752. Brunswick, Hermann. tJber das Vorkommen von Gipskrystallen bei den Tamari- 

 caceae. [The occurrence of crystalline calcium sulphate in Tamaricaceae.] Sitzungsber. 

 Akad. Wiss. Wien (Math.-Nat. Kl.) Abt. I, 129; 115-135. 1 pL, 1 fig. 1921.— Crystals 

 occurring in epidermal cells of species of Tamarix were found to be water soluble, hence not 

 calcium oxalate as previously supposed. Their identity as calcium sulphate, CaS04.2H20, 

 was established by microchemical and gross analysis and by their crystallographic properties. 

 Similar crystals occur in the following genera of Tamaricaceae: Reaumuria, Myricarin, and 

 Hololachne. They are not found in Fouquieria, which upon other grounds as well may be 

 segregated in a separate family. The crystals occur most commonly in green and growing 

 tissues, such as leaf mesophyll and veins, vascular bundles and sclerenchymatous elements 

 in the stem, and the various flower parts. Their origin is related to the xerophytic habitat 

 of these plants. The soil water with which the roots are in contact is rich in calcium and mag- 

 nesium compounds. The excess of sulphate is deposited in the epidermal cells, owing to its 

 slight solubility, while chlorides and carbonates are excreted and accordingly deposited as 

 a crust on the outer surface. In cultivation these plants continue to show cr3'stalline deposits 

 in the epidermal cells, but the external crust is absent; this is attributed to selective absorp- 

 tion of SO4 as an essential ion. — F. Weiss. 



753. KoHLER, D. [Rev. of: Weis, F. Vandkulturforsog i forskellige naeringsoplosninger, 

 specielt til belysning af manganets eg brin-tion-koncentrationens betydning. (Culture experi- 

 ments with different nutrient solutions, particularly the importance of manganese and the hydro- 

 gen ion concentration.) Meddedel. Plantefysiol. Lab. K0benhavn 239-2S0. 1919.] Rev. G^n. 

 Bot. 33 : 221-222. 1921. 



754. MicHEELs, H. Note au sujet de Taction des sels de sodium et de potassiimi sur la 

 germination. [The action of salts of sodium and potassium upon germination.] Rec. Inst. 

 Bot. L60 Errera (Bruxelles) 10: 161-167. 1921.— Very dilute solutions (1/100 and 1/1000 M.) 

 of KCl, KNO3, NaCl, and NaNOs differ very little in electrolytic dissociation, so that in this 

 study a favorable comparison may be made of these salts. In reference to toxicity, and 

 when no current is passed through, it is found that Cl>No3 and Na>K. A favorable 

 influence in respect to length of leaves and weight of plant lets produced is exerted by NO3, 

 likewise this ion induces an elongation of the root hairs not observed with CI. Although 

 more toxic than K, Na augments the length of roots more than the former. Equivalent results 

 are obtained when the solutions are electrolyzed. The action of the anions occurs in the 

 cathodized solutions, and that of the cathions in the anodized. It is to special phj'siological 

 properties of the ions, not measurable as chemical properties, that it is necessary to 

 attribute the differences observed. — Henri Micheels. 



PHOTOSYNTHESIS 



755. Moore, Benjamin. Light as the source of life. Scientia 28: 361-371. 1920. — 

 Inorganic colloids activated by radiant energy are to be regarded as a stage in the evolution 

 of the microorganism. — William W. Diehl. 



756. Regnier, M. [Rev. of: Henrici, M[arguerite]. De la teneur en chlorophylle et 

 de I'assimilation du carbon des plantes des Alpes et des plaines. (The chlorophyll content and 

 the assimilation of carbon in plants in the Alps and on the plains.) Verhandl. Natur. Ges. 

 Basel 30: 43-136. 1919 (1920).] Rev. G6n. Bot. 33: 222-224. 1921. 



