166 
Physiologie. 
ammonium, salts, have lately become quite unhealthy, with spreading 
barren patched covered with peat-like decayed Vegetation. These 
soils often fail to set up nitrification when inoculated into suitable 
media and they are distinctly acid to litmus paper. 
This research proves that the acidity has arrested the nitrifi¬ 
cation except where small pieces of chalk occur locally and neutra- 
lise the free acid. 
It seems clear that in the absence of sufficient oxidised nitrogen 
the grasses must have drawn directly upon the ammonium salts. 
The acidity of the soil seems to correspond to the Chlorides and 
sulphates supplied in combination with ammonia as manure and no 
doubt some free humic acid is present. 
If dextrose and ammonium sulphate media are inoculated with 
this soil Penicillium developes vigorously and consumes the sugar 
and ammonia leaving free sulphuric acid which may rise to 1 / 80 N 
and then growth is arrested. This is about the degree of acidity of 
the soil-water of these grass-plots and as moulds were found to be 
abundant in the decaying Vegetation it seems that the whole cycle 
is clearly explained. F. F. Blackman. 
Hill, T. G., Observations on the osmotic properties of the 
root-hairs of certain salt-marsh plants. (New Phytologist. 
Vol. VII. p. 133 — 142. with several figures. 1908.) 
These observations were made in the salt marshes of the Bouche 
d’Erguy where rapid alterations of salinity of soil-water were deter- 
mined under the conflicting influences of rain and tides. 
In regions of high salinity the root hairs of Salicornia and Suaeda 
may have an osmotic pressure equivalent to 6,7°/ 0 NaCl, and this 
was found to be soon reduced by sojourn of the roots in fresh 
water. On submerging these acclimatised roots in sea water their 
osmotic equalivent, as determined by plasmolysis experiments soon 
rose again. 
Drabble and Lake have made analogous observations. 
Osterhout has drawn attention to lack of injury to delicate 
sea-weeds in passing from salt to fresh water and this may be due 
to internal alterations as above. F. F. Blackman, 
Laborde, J„ Sur les transformations de la matiere chromo- 
gene des raisins pendant la maturation. (C. R. Ac. Sc. Paris. 
CXLVII, 26 octobre 1908. p. 753.) 
Dans une precedente note (C. R. 20 juin 1908), J. Laborde a 
montre que la coloration des pellicules des raisins rouges a pour 
origine une transformation de l’oenotanin. La matiere chromogene 
de la pellicule qui est sous la forme insoluble ä l'etat vert se solu- 
bilise de plus en plus au cours de la maturation. La solubilisation 
des matRres tannoides de reserve a lieu vraisemblablement par une 
action diastasique, mais la recherche directe de cette diastase par les 
procddes donnant la zymase de Büchner a ete sans resultat. 
Jean Friedei. 
Laborde, J., Sur Porigine de la matiere colorante des raisins 
rouges et autres Organes vegetaux. (C. R. Ac. Sc. Paris. 
CXLVI. p. 1411. Paris 29 juin 1908.) 
Laborde a retire de raisins verts de cepages rouges ou blancs 
