ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
561 
mona are duo to a hygroscopic mechanism, at least as probably as that 
which attributes them to a shrinking of the cell- walls. 
(4) Chemical Changes (including Respiration and Fermentation). 
Functional Metabolism in the Plant.* — In the Croonian lecture 
delivered before the Royal Society, Prof. W. Pfeifer discusses the nature 
and significance of functional metabolism in. the plant. The true aerobic 
functional metabolism is the same in principle in plants and in animals. 
This process runs its course within the living protoplasm, not merely 
on its surface, or in particular portions of it, but in and between all 
its constituent parts. The distinction between aerobic and anaerobic 
organisms is one of degree only ; the two are connected together by 
intermediate links. Among aerobes life is maintained for a limited 
time by the action of intramolecular respiration. 
Influence of Sodium and Magnesium Salts on the Growth of 
Plants.f — According to a series of experiments made by M. H. Coupin, 
maritime plants ( Beta maritima , Atrijplex hastata var. maritima , Ccihile 
maritima) are very closely adapted to the proportion of sodium chloride 
contained in sea-water, a very small increase in the proportion of that 
salt in the water killing them. This, however, is not -the case with 
magnesium salts ; the proportion of magnesium chloride may be trebled 
or even quadrupled. 
Depletion of the Endosperm of Barley during Germination. f — • 
According to experiments made by Mr. H. J. Brown and Mr. F. Escombe 
on the germination of barley, the separation of the “ aleurone-layer ” or 
Kleberschicht is due to cytohydrolysis, i.e. to the absorption of water by 
the hyaline portions of the cytoplasm, and the disintegration due to this 
cause extends centripetally into the endosperm. They affirm that the 
normal phenomena of endosperm solution and depletion are not due to 
the action of extraneous micro-organisms, but to the metabolic activity 
of the endosperm itself; and not to its amyliferous cells, but to the 
aleurone-layer alone. This layer is the only part of the endosperm which 
can be recognised as taking part in the preparation of the food-material 
for the embryo, since no evidence can be obtained of any changes being 
initiated by the amyliferous cells themselves. The “ aleurone-cells ” 
share with the scutellum the power of eroding starch-grains, but their 
principal function is to break down the cell-membranes of the amyli- 
ferous endosperm. 
Chemical Processes in the Germination of Seeds.§ — Mr. F. Escombe 
supports the view of Gorup-Besanez that during germination amides and 
amido-acids perform different functions. The former result in only 
small amounts from direct hydrolysis, being chiefly formed synthetically 
from the further transformation of amido-acids, and of nitrogenous sub- 
stances derived from the reserve-carbohydrates. This synthesis of 
amides occurs in the dark ; and the further stages of proteohydrolysis, 
at any rate, are due to enzymic action. It is also most probable that 
* Proc. Roy. Soc., lxiii. (1898) pp. 93-101. 
t Rev. Gen. de Bot. (Bonnier), x.(1898) pp. 177-91 (3 figs.). 
j Proc. Roy. Soc., lxiii. (1898) pp. 2-25 (1 pi.). Nature, Iviii. (1898) pp. 332-4 
(2 figs.). § Science Progress, vii. (1898) pp. 219-36. 
