1017] AGRICULTURAL BOTANY. 329 



diastatic action in solutions of soluble starch by the precipitation of the undi- 

 gested starch and part of the dextrins in acid alcohol. An account is also given 

 of the effects as to the amount of starch digested by P. camembcrtii which are 

 produced by given concentrations of various salts. A contrast is noted between 

 the rate of digestion of soluble starch by P. caniembertii and Aspergillus oryzw 

 and the rate observed in the case of digestion by Mucor rouxii or Fusarium sp. 

 While no evidence was found to connect potassium and calcium with diastase 

 formation, it is thought that nitrogen may bear an intimate relation thereto in 

 case of P. caniembertii. 



Nitrates in suUa (Heydsamm coronarium) and other legumes, Giulia 

 Campanile {Ann. Bot. [Rome], 14 (1916), No. 1, pp. Jf9-75). — In the studies here 

 outlined, employing chiefly H, coronarium, it was found that plants gi'owing 

 in a medium rich in nitrates absorbed these in a quantity somewhat larger 

 than in ordinary soil, especially in case of the young plants. The distribution 

 of nitrates in the plant at different periods is discussed. Data are also pre- 

 sented as obtained with Lupinus albus, these corresponding in a general way 

 with those obtained with Pisum sativum, Vicia faba, and V. sativa. 



Glucosid formation by plants, G. Giamician and C. Havenna {Atti R. Accad. 

 Lincei, Rend. CI. Sci. Fis., Mat. e Nat., 5. ser., 25 {1916), I, No. 1, pp. 3-7).— 

 In tests with maize and bean it was found that while pyrocatechin, gallic acid, 

 and tannin were toxic to both these plants, saligenin was used by both, benzyl 

 alcohol probably by bean, and hydroquinone apparently by maize. It is stated 

 that substances resembling glucoslds were formed in the young plants. 



Studies on the presence and the physiological significance of the flavone 

 derivatives in plants, I— III, K. Shibata, M. Kishida, and I. Nagai {Bot. Mag. 

 [Tokyo], 29 {1915), Nos. ii43, pp. 118-132, figs. .J; 3J,7, pp. 301-308: 30 {1916), 

 No. 352, pp. 149-178). — In the first of these papers it is claimed that the flavone 

 derivatives, probably as glucoslds, were present invariably in the epidermal cell 

 sap, and sometimes in the deeper structures, of the aerial parts of numerous 

 plants examined. These substances are held to be of considerable physiological 

 importance, probably in preventing injury from ultraviolet rays. 



In part II, entitled The Chemical Biology of Alpine Plants, further experi- 

 ments and observations are reported which are considered to support the con- 

 clusions stated in the preceding article. Flavone bodies were found to be 

 among those occurring most commonly in plants, such as chlorophyll, sugars, 

 and starches. They appear to be related to the penetrability of atmosphere to 

 light, probably serving to protect the plant from the short ultraviolet wave 

 lengths, in case of plants growing in tropical or high regions, and hence acces- 

 sible to these shorter ultraviolet rays. 



In part III, entitled The Flavone Content of Tropical Plants, a large body 

 of studies carried out with very diverse plants in various parts of the world 

 is said to confirm the conclusions above stated as regards the relation between 

 flavone and protection from ultraviolet waves of solar origin. Flavone bodies 

 and anthocyanin are said to pass reversibly the one into the other, the former 

 being regarded as an important physiological factor in plant life. Some of the 

 data are reported in tabular form. 



Kelation of oxidases and catalase to respiration in plants, C. O. Appleman 

 {Amer. Jour. Bot., 3 {1916), No. 5, pp. 223-233).— This information has already 

 been noted from another source (E. S. R., 34, p. 523). 



On the relation between transpiration and stomatal aperture, F. Darwin 

 {PJiil. Trans. Roy. Soc. London, Ser. B, 207 {1916), No. 343. pp. 413-437, figs. 

 23). — The problem which furnishes the subject matter for the present paper, 

 the relation between stomata and transpiration, has already been dealt with to 



