19171 AGRICULTUKAL BOTANY. 25 



during germination there is a distinct relation between the disappearance of 

 amino acids and the accumulation of amids, as determined by methods which 

 are described and claimed to be more strictly quantitative than those formerly 

 employed. The investigation consisted in following the changes of the total 

 and water-soluble nitrogen, and the various compounds of the latter, in the 

 etiolated pea plant, which lent itself readily to this purpose and to the methods 

 which are describetl. 



It is stated that in the shoot the percentage of total nitrogen more than 

 doubled in 26 days, but only in cases in which carbohydrate decomposition 

 exceeded protein disintegration. This fact supposedly indicates that during 

 the early stages of growth rapid carbohydrate catal)olism occui-s in the shoot. 



Total nitrogen decreased in the cotyledon, and during early growth a-amino 

 acids accumulated in the cotyledon more than in the shoot. Catabolism is 

 therefore thought to be the predominant type of change in protein material 

 during germination. Water-soluble nitrogen showed a nearly constant pro- 

 portion to the total nitrogen except in the first stage of growth, when it accu- 

 mulated considerably. Ammonia, only traces of which occurred in the seed, 

 accumulated during germination. Its flucfuations roughly paralleled those of 

 amid nitrogen, but it decreased in the shoot. Amid nitrogen increased in the 

 shoot throughout all stages of germination, but not so considerably as reported 

 by previous investigators. 



Since amids accumulated while carbohydrates and ammonia decreased, it 

 is suggested that the former may have been produced synthetically from the 

 latter compounds. The a-amino acids accumulated rapidly, especially in the 

 cotyledon, during early growth, but later they decreased in the shoot and dis- 

 appeared from the cotyledon. The accumulation of amids simultaneously with 

 the decrease of the a-amino acids and ammonia in the shoot is considered to 

 indicate that a-amino acids serve for amid production in the nitrogen metabolism 

 of the etiolated pea plant. 



The release of oxygen separated during the reduction of nitrates in green 

 plants, M. MoLLiAED {Conipt. Rend. Acad. Sci. [Paris], 163 (1916), No. 15, pp. 

 S71-S73). — A study of the behavior of radish grown under contr9lled conditions 

 as regards space and nutritive medium is described. The results appear to indi- 

 cate that for the fixation of one atom of nitrogen there was a corresponding 

 disengagement of two atoms of oxygen. 



Observations on the cytological formation of anthocyanin in living plants, 

 M. MiRAKDE (Compt. Rend. Acad. Sci. [Paris], 163 {.1916), No. 15, pp. 368- 

 STl). — The author has extended to lower plants the studies regarding the mito- 

 chondrial origin of anthocyanin, which had been pursued among higher phmts 

 by Guilliermond (E. S. R., 35, p. 523), employing for this purpose Azolla 

 filiculoides, which lends itself readily to direct observation in this connection. 



He states that he has been able to obtain fresh evidences of the mitochondrial 

 origin of anthocyanin pigment. In case of A. filicjiloides, anthocyanin is se- 

 creted by granular mitochondria, which in due time emigrating from the 

 central vacuole of the cell become impregnated with a phenol compound which 

 gradually develops anthocyanin pigment. In cases of extreme reddening the 

 anthocyanin is dissolved in the vacuole. 



Selective permeability: The absorption of phenol and other solutions by 

 the seeds of Hordeum vulgare, A. J. Bkown and F. Tinker (Proc. Roy. Soc. 

 [London], Ser. B, 89 {1916), No. B 617, pp. 313-379, figs. 2).— Previous study 

 (E. S. R., 34, p. 626) on the absorption of aqueous solutions by barley seeds 

 has related mainly to the phenomena attending diffusion of the solvent through 

 the semipermeable seed covering, which is permeable also to certain classes 

 of contained solutes (as phenols and fatty acids), behaving, in fact, rather 



