1895.] Vegetable Physiology. 1011 
at Geisenheim on the Rhine, has gone over the same ground in a long 
series of experiments (Ist die Transpirationsgrisse der Pflanzen ein 
Maassstab fiir ihre Anbaufihigkeit? Landw. Jahrb., Bd. 24, 1895, 
H. 3, pp. 503-537) which throw doubt on Miiller-Thurgau’s methods 
and lead to the following opposite conclusions : (1) In determining 
the amount of transpiration the entire decrease in weight of the plant 
and apparatus must be taken into account and not simply the decrease 
of water in the flasks, since under pressure, in short experiments, the 
error resulting from the forcing into the wood of water which is not 
transpired is very considerable. (2) The demonstrated transpiration 
of any branch can never be taken as a measure of the transpiration of 
the whole tree. (3) The amount of transpiration of different branches 
of the same tree may be wider apart in many cases than that of 
branches of different trees or even of different varieties. (4) In par- 
allel experiments, under exactly the same transpiration conditions, the 
ratio of the amount of water given off by different branches is by no 
means constant. (5) The influence and interchange of the different 
factors governing transpiration is quite different in different individ- 
uals. (6) The present condition of the individual and the circum- 
stances under which it previously transpired have a great influence 
upon transpiration. (7) It follows that the amount of transpiration 
of a single individual cannot be regarded as a measure of the water 
requirements of the whole variety. According to the writer, Müller- 
Thurgau has also left out of account the capacity of individuals and 
varieties to adapt themselves to changed conditions—-Erwiy F. 
MITH. 
ZOOLOGY. 
A Stratified Lake Fauna.—One of the most interesting results 
achieved by the naturalists of the Russian Biological Station on the 
island of Solowetzk in the North Sea, has been the discovery of a re- 
markable lake on the island of Kildine in the Arctic Ocean. This 
lake, which is completely separated from the sea by a narrow strip of 
land, was discovered by the Russian naturalist, M. H. Herzenstein, 
who was struck by finding in the lake a fish which is exclusively 
marine in habit, namely, the common cod. Further observations by 
MM. Faussek and Knipowitsch have elucidated the peculiar features 
of the fauna of the lake. On the surface the water is fresh, and is in- 
