Physiologie. 193 



ses, and by the application of thcse methods it is shown that in 

 Priniuln sinensis tiie distribution of oxydases in thc tissues coincides 

 with that of the pii^ments of thc llower aiid othcr parts of the plant. 

 It is found that P. si)iensis contains tvvo peroxydases which differ 

 in Chemical reactions and in localisation; and that dominant white 

 flowers contain a substance which inhibits but does not destroy 

 Peroxydase. Experiments with recessive white flowers, the genetical 

 behaviour of which indicates that they lack either Peroxydase or 

 chromogen, show that they contain Peroxydase; inasmuch as reces- 

 sive whites contain no inhibitor of oxydase, failure to form pigment 

 is to be attributed lo lack of chromogen. The distribution of per- 

 oxydases in P. sinensis is regarded as typical of that in flowering 

 plants generally, and the raethod appears to be capable of wide 

 application in the study of the distribution of oxydases. 



F. Cavers. 



Armstrong, H. E., E. F. Armstrong and E. Horton. S tu dies 

 on enzyme actio n. XVI. The enzymes of emulsin 1): 

 Prunase, the correlate of prunasin. (Proc. Roy. Soc. 

 LXXXV. 580. p. 359—362. 1912.) 



In previous studies in this series, evidence has been adduced 

 that the diglucloside amygdalin is resolved into glucose, benzal- 

 dehyde, and hydrogen Cyanide by two distinct enzymes in the 

 emulsin prepared from the almond fruit, one (amygdalase) serving 

 to resolve it into glucose and prunasin, the other to convert the 

 prunasin into glucose, benzaldehyde, etc. Amygdalase is known to 

 occur in certain yeasts unaccompanied by the second enzyme. It is 

 now shown that the second enzyme occurs in the leafof the almond 

 and of other species of Prumis from which prunasin, but not 

 amygdalin, may be separated; it is proposed to term this enzyme 

 prunase. Apparently the two enz5'-mes are always present in the 

 ■fruit in association with amygdalin, but amygdalin is not known to 

 occur in the leaf, and the leaf enzyme as a rule has little action 

 on amygdalin. " F. Cavers. 



Armstrong. H. E., E. F. Armstrong and E. Horton. Studies 

 on enzyme action. XVII. Enzymes of the emulsin type 

 2): The distribution off^-enzymes in plants. (Proc. Roy. 

 Soc. LXXXV. 580. p. 363-369. 1912.) 



A method of general application is described by which the 

 •enzymic activity of plant Juices, etc., may be determined. It has 

 been applied to the study of the distribution in plants of enzymes 

 capable of acting upon the glucosides linamarin, prunasin, salicin, 

 arbutin, and amygdalin. See the following paper. F. Cavers. 



Armstrong, H. E. and J. V. Eyre. Studies on enzyme 

 action. XVIII. Enzymes ofthe emulsin type 3): Linase 

 and other enzvmes in Linaceae. (Proc. Roy. Soc. LXXXV. 

 580. p. 370—377. 1912.) 



The method developed in the preceding paper (see above) for 

 determining the distribution of enzymes of the emulsin type has 

 been applied to various species belonging to the family Linaceae. 

 This family was found to be divisible into two groups. Oneofthese, 

 •which apparently includes all species similar in habit to Linum 



Eotan. Oentralblatt. Band 123. 1913. 13 



