40 Physiologie. 



nous. The authors observed that when the dried unripe plant 

 is crushed with water and allowed to stand for a iew hours it 

 develops a strong odor of HCN. This acid was present: as 

 much as 0,345*^/o, whilst in younger plants only 0,263*^/0 was 

 obtained. When the plant is extracted with alcohol no prussic 

 acid (HCN) is obtained, nor is any iormed when the plant is 

 treated with boiling water. The extracts had considerable re- 

 ducing action on alkaline copper Solutions. From these facts it 

 was inferred that the plant contains a glucoside and an hydro- 

 lysing enzyme. 



The authors obtained from the alcohoiic extract of the plant 

 the glucoside to which they give the name lotusin and the for- 

 mula C28H3iOjgN. On hydrolysis, lotusin gives rise to 

 dextrose, prussic acid (HCN), and a yellow substance termed 

 lotof lavin (CisHioOn). The authors investigated the Com- 

 pound derived from lotoflavin by various reagents: on treat- 

 ment with fused potash, phlorogiucinol is one of the products, 

 and alkaline liquids cause the formation of lotosinic acid. Loto- 

 flavin is isomeric with two other yellow colouring-matters of this 

 class, viz. f i s e t i n (f ustic, Rhiis Citinus) and 1 u t e o 1 i n 

 {Reseda hiteold). The decomposition products obtained with 

 fused potash were found to be identical with those given by 

 Morin for Morus tinctoria. 



The chloroform-water extract of the plant was found to 

 contain proteolytic and amylolytic enzymes, as well as the enzyme, 

 lotase, which hydrolyses lotusin. Lotusin is not hydrolysed 

 by diastase or invertase, and only slowly by extract of sweet 

 almonds (emulsin): hence lotase would appear to be a specific 

 enzyme for lotusin. 



Lotusin and amygdalin are the only glucosides definitely 

 known to produce prussic acid (H C N) on hydrolysis. 



S. H. Vines. 



Blackman, f. f. and Matthaei, G. L. C, On the Reaction 

 of Leaves to Traumatic Stimulation. (Ann. Bot. 

 Vol. XV. 1901. p. 553.) 



The authors, in the first place, draw attention to the fact that 

 leaves, provided with moisture, will remain healthy in darkness 

 for a very long time; in the case of Prunus Lauro-cerasus, for 

 as many as fifty days. The remarkable vitality of leaves made 

 it possible for the authors to study the effects of injury to them. 

 If a leaf of P. Lauro-cerasus be cut with a sharp knife, no 

 healing reaction follows. The cells that are actually cut through, 

 and those of a few adjacent layers, die but never in sufficient 

 number to produce a visible brown edge to the wound. 



If, on the other band, a sufficient number of cells be killed 

 to produce a brown edge — by a blow, or burning with a 

 hot iron — a peculiar healing reaction follows: the healthy 

 tissues round the wound cut off and exfoliate the injured area 

 so that it falls out leaving a hole in the leaf. The spongy pa- 



