1018 SUMMARY OF CURRENT RESEARCHES RELATING TO 



latter case it is not affected to any considerable extent by the opposite 

 incisions. These facts are regarded by the authors as opposed to the 

 imbibition theory; and as explicable only on tbo hypothesis that the 

 movement takes place in the cell-cavity. In the Coniferee the water 

 can still move from tracheid to trachcid notwithstanding the incisions ; 

 while in Angiosperms, all the vessels being cut, the conduction is 

 rendered difficult. 



Photochemical Studies.* — Ilerren H. Brunner and E. Chuard 

 record the following results of experiments on the chemical constitu- 

 tion of living plants. Glycoxylic acid occurs in very young grapes, 

 together with succinic acid, also in unripe apples, plums, currants, 

 gooseberries, and in rhubarb. The petiole of the rhubarb leaf also 

 contains succinic, malic, and oxalic acids, together with potassium 

 nitrate. The authors have also detected in the sap of plants an acid 

 termed by them gluco-succinic ; and either this acid or its nearly 

 related glucoside is stated to be present also in the gooseberry, cur- 

 rant, and banana. 



Action of Chlorophyll separated from respiration.! — MM. G. 

 Bonnier and L. Mangin have attempted to estimate the amount of 

 gases exchanged in the living plant by the action of chlorophyll 

 alone compared with that due, during the same period, to respiration. 

 It is difficult to arrive at any definite conclusions ; but it may be 

 stated, as a general result, that, while the volume of oxygen disengaged 

 corresponds nearly to that of carbonic acid absorbed, the results are 

 not uniform when the two functions are separated ; the amount of 

 oxygen absorbed often exceeds that of carbonic acid disengaged in 

 respiration alone ; while the oxygen disengaged often exceeds the 

 carbonic acid absorbed in the action of chlorophyll by itself. These 

 two processes, in fact, seem in a certain sense to compensate one 

 ancther. 



Influence of Ether and Chloroform on Plants.^ — By experiments 

 on Salix viminalis, the pea, hemp, and Saccharomyces cerevisise, Herr F. 

 Elfving finds that small doses of either of these anesthetics in certain 

 cases favour respiration, viz. up to 5 per cent, for chloroform and 

 15 per cent, for ether; above these proportions they act injuriously. 

 As little as 2 per cent, of chloroform has a perceptible effect in 

 retarding the germination of hemp-seeds. In the case of Saccharo- 

 myces cerevisise, from 1 to 8 per cent, of ether has no sensible effect on 

 respiration. The intensity of alcoholic fermentation is affected by 

 even so small a proportion as 1 per cent. The growth of Phycomyces 

 nitens is not affected by ether in the proportion of 1 per cent. ; 4 per 

 cent, retards, and 5 per cent, altogether stops it. The sensibility to 

 light of germinating spores of Chlarnydornonas pulvisculus is increased 



* Ber. Deutsch. Chem. Gesell., 1886, pp. 595-622. See Bot. Ztg., xliv. 

 (1886) p. 426. 



t Ann. Sci. Nat. (Bot.), iii- (1886) pp. 5-44. 



\ Ofvers. af Finska Vetensk.-Soc. Forhandl., xxviii. (1886). See Bull. Soc. 

 Bot. France, xxxiii. (1886) Rev. Bibl., p. 64. 



