86 Physiologie. — Lichenes. 



Lepeschkin regards tiie lipoids present in the plasma-mem- 

 brane as being loosely combined with the proteids of the plasma. 

 A Short summary account is given of Lepeschkin's vieuws as to 

 the Constitution of the plasma-membrame. 



The author (Blackman) considers it "by no raeans easy to 

 correlate in any accurate way the results obtained by Czapek and 

 Lepeschkin". Undoubtedly the chemistry of the protoplast is a 

 matter of microchemistry and the laws of absorption dominate the 

 Situation, but the primarj' difficulty is the incertainty as to how 

 far the principles of surface-action and microchemistry in a perfect 

 fluid apply to protoplasm. All lines of investigation point to the 

 presence of lipoids in the plasmatic membrane, but while Lepesch- 

 kin inclines to the view that the lipoid present is lecithin combined 

 with the Proteid, Czapek's evidence is in favour of a saturated 

 emulsion of neutral fat; these two views are briefly considered by 

 the author. E. de Fraine. 



Blackledge, L. M., Variations in the NaCl content of Non- 

 Halophytes. (Ann. Bot. XXVII. p. 168—171. 1 Table in the Text. 

 Jan. 1913.) 



Analyses of the leaf-ash of plants of Acer Pseudo-platanus, Ul- 

 mus campestris and Hex aquifoUuni, grown on ihe sea shore and 

 at varying distances from it, were made; the amount of NaCl in 

 the soil water was also determined. 



The results shewed that a large amount of NaQ in the soil 

 does not necessarily mean a large amount in the leaves, nor vice 

 versa. Evidence is brought forward to shew that variations in the 

 NaCl content of the plant are due to variations in the amount of 

 NaCl present in the atmosphere and absorbed by the leaves directly. 



E. de Fraine. 



Wager, H. A., Respiration and Cell Energy. (Trans. Roy. 

 Soc. South Africa. II. 5. p. 405—417. 1912.) 



The author's summary is as follows: 



The energy required in the metabolism of colourless cells is 

 not obtained from the sun either directly or indirectly. The proto- 

 plasm in colourless cells only uses energy set free by some che- 

 mical Union taking place, either in the cell, or by the introduction 

 of internal elements into the cell. In no case is energy obtained by 

 the decomposition of the substances of the cell, as indeed energy 

 is required to bring about such a decomposition. 



Energy is not required for the synthesis of Compounds for 

 which Chemical afifinity is responsible, although undoubtedly che- 

 mical affinity is inextricably connected with energy. No plant con- 

 tains a störe of directly available energy. 



Respiration is not a process apart from nutrition. The term 

 should be used exclusively to mean the interchange of gases taking 

 place in each individual cell. Water is the respiratory medium for a 

 large number of the living cells in trees. A. D. Cotton. 



Knowles, M. C, Notes on West Galwav Liehen s. (Irish 

 Naturalist XXI. p. 29—36. 1912.) 



An account of the lichen-flora of a windswept-treesless district 



