AGRICULTURAL BOTANY. 725 



of I'ice ami maize were grown iu a sterilized luitrieut medium eontaiiiiiig dilute 

 sodium nitrite tlieir roots were able to absorb without further oxidation por- 

 tions of the nitrite present with no injurious effects on the seedlings. 



Investigations on the absorption of nitrogenous organic substances by the 

 roots of phanerogams in a carbon dioxid free atmosphere, Y. Gkafe {Sitzber. 

 K. Akad. Wiss. IVicnna], Math. Naturw. KL, 118 (1909), I, No. 7, pp. 1135- 

 1153). — The results are given of experiments on the utilization of nitrogenous 

 organic matter by Phaseolus I'ldgaris when grown in an atmosphere free of 

 carbon dioxid. In these experiments 5 amids, namely, tyrosin, glycocoll, alaniu, 

 oxamid, and leucin, were used, both combined into one mixture and singly, as 

 the source of the nitrogenous matter. 



It was found that the presence of the amids iu no wise compensated for the 

 lack of carbon dioxid. On the contrary, the seedlings died as soon as their 

 reserve food in the cotyledon had been used. Further, the amids produced a 

 poisonous action on the seedlings which showed itself mainly on the root system. 



The formation of glucosids by plants, G. Ciamician and C. Ravenna (Atti 

 R. Accad. Lincci, RcikL CI. ^V/. Fis., Mat. c Nat., 5. scr., 18 {1909), II, No. 12, 

 pp. 59.'f-596; ahs. in Jour. Chcm. Soc. [London], 98 (1910), No. 569, II, pp. 23^, 

 235). — The authors report that not only the maize plant but also a mass of 

 triturated maize is able to decompose salicin and also to transform aromatic 

 substances such as saligenin, catechol, and possibly quinol and mandelonitrile 

 into glucosids. 



A study of hydrocyanic acid in Sambucus, C. Ravenna and M. Tonegutti 

 (Staz. Spo: Agr. Itah, li (1909), No. 10-11, pp. 855-879).— An investigation 

 was made of the hydrocyanic acid in the leaves of 8. nigra. 



It was found that the leaves contained an emulsin capable of decomposing 

 sambunigrin. The enzym is not soluble in water, and all the hydrocyanic acid 

 occurring in the plant is in the form of glucosids, which appear to be more 

 abundant than previously reported (E. S. R., IS, p. 126). The greater propor- 

 tion of the glucosid is found iu the petioles of the leaves. The authors hold 

 that their experiments do not support the theory that the glucosid is formed 

 directly from carbohydrates and nitrates in the leaves, as is the case with 

 sorghum, and they do not believe that the glucosid serves as a reserve material 

 so far as the leaves themselves are concerned. 



The simultaneous liberation of oxygen and carbon dioxid during the dis- 

 appearance of anthocyanin in plants, R. Combes (Compt. Rend. Acad. Sci. 

 [raris], 150 (1910), No. 23, pp. 1532-153Jf).—ln a previous publication (E. S. R., 

 23, p. 528) the author has given an account of the I'ole of oxygen in the forma- 

 tion and destruction of anthocyanic pigments in plants. 



In continuing his experiments studies were made of the gaseous exchanges 

 taking place in red leaves of Ailanthus glaiidnlosn taken just as they were 

 losing their red color. Such leaves in the light were found to give off both 

 carbon dioxid and oxygen in appreciable quantities when compared with normal 

 leaves under similar c(mditions. 



This has led the author to conclude that red leaves during this particular 

 jieriod of develoimient suffer a consi(leral)le loss of carbon and oxygen, the lat- 

 ter both in the form of carbon dioxid and as free oxygen. Similar phenomena 

 are said to occur in many fleshy plants. 



Experiments on the transformation of the starchy and fatty contents of 

 plants, especially of trees, F. Weber (Sitzbc?: K. Akad. Wiss. [Vienna], Math. 

 Natunr. A'/., 118 U'J09), I, No. 7, pp. 967-1031). — As a result of the author's 

 investigations it is chiimed that the processes of fat formation and of starch 

 solution are periodic, but that the former is not, as heretofore supposed, lim- 



