254 
Physiologie. 
A few representatives of each of the four main classes of vegetable 
proteins are described in some detail. F. F. Blackman. 
Smith, A. M., Physiologv of Plants in the Tropics. (Proc. 
Cambridge Phil. SÖc. XIV,'p. 296—297. 1907.) 
a. The Internal Temperature of Leaves under Tropical 
Insolation. In still air this temperature may rise 15°C. above the 
shade temperature; movement of the air rapidly reduces this excess 
temperature. Leaves with their upper surfaces placed together were 
consistentlv cooler (average 2.5° C.) than leaves with stomatic sur¬ 
faces pressed together. Red leaves show a higher internal tempera¬ 
ture, thermoelectrically measured, than white ones by 2—4° C. 
b. Periodicity of growth in Ceylon. Some plants with red 
foliage grow most actively in the driest month and it is suggested 
that only then is there sufficient transpiration to bring up the 
required salts. 
c. Respiration of Hydrilla verticillata, a tropical waterweed. 
The respiration from 7°—50° C. augments according to the van ’tHoff 
rule with a coefficient of 2.2 for 10° C. There was no sign of an Op¬ 
timum temperature. F. F. Blackman. 
Steward, F., On Endospermic Respiration in certain Seeds. 
(Annals of Botany, Vol. XXII, p. 415—448. 1908.) 
Experiments ha^e been made on the C0 2 -output of endosperms 
of Hordeum and Zea freed from embryo and in some cases from 
aleurone layer under antiseptic conditions. The existence ofagaseous 
exchange of a respiratory nature is proved but there is no decision 
as to whether it is to be attributed to vitality of protoplasm or 
action of respiratory enzymes. 
Previous theories as to the vitality of the aleurone layer in 
particular are reinforced by these respiration experiments. 
Per grm. of fresh weight the respiration of the embryo alone 
is, in Barley, seventeen times that of the endosperm but as the 
endosperm weighs about seventeen times as much as the germ, 
these parts presumably halve the respiration of the intact seed 
between them. In Zea the isolated embryo respires six times as 
much as the endospermic remainder. 
Twenty four hours in water saturated with Chloroform does not 
much diminish the C0 2 -output of degermed Barley endosperm but 
4°/ 0 formaldehyde quite stops it. F. F. Blackman. 
Brusehi, D., Researches on the vitality and self-digestion 
of the Endosperms of some Graminaceae. (Annals of Botany, 
Vol. XXII, p. 449—463. 1908.) 
This paper is a resume of several papers published in Italian, 
1906—1907. The authoress has observed the evacuation of the stored 
starch in isolated endosperms of Maize, Barley, Wheat & Rye by the 
method of Hansteen, using columns of plaster of Paris in water 
to conduct away the sugars from the endosperm. 
She has shown that the amyloclastic and cytoclastic enzymes 
that occur are rarely the result of revived vital aetion of the endo¬ 
sperm cells but are formed from pro-enzymes which were present 
in the resting tissue. 
