ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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lactic acid and their salts acted powerfully, butyric acid and asparagin 
with less energy ; the action is again attractive or repulsive, according 
to the concentration. With JEthalium septicum positive results were 
also obtained with valerianic and propionic acids. The plasmodes 
of this species are apparently influenced by the same irritants as the 
myxamoebm. 
(4) Chemical Changes (including Respiration and Fermentation). 
Chemical Changes during Germination.* — Mr. H. T. Brown and 
Dr. G. H. Morris describe the phenomena of metabolism which take 
place during the germination of the grain of some grasses, especially 
barley. They state that a disintegration and dissolution of the cell- 
walls of the endosperm always precede any attack upon the cell- 
contents, and that this depends on the production during germination of 
a special cellulose-dissolving or “ cyto-hydrolytic ” enzyme, which, like 
diastase, is soluble. Owing to the non-diffusible nature of the “ amylo- 
hydrolytic ” enzyme, or diastase, the previous breaking down of the 
cell-wall is a necessary prelude to the dissolution of the contained starch- 
grains. The appearance of both these hydrolysts is due to a specialized 
secretory function of the layer of columnar epithele which covers the 
outer surface of the scutellum. 
The authors support the view that the relation of the embryo to the 
endosperm is that of parasite to host, and they found it possible to 
cultivate the excised embryo after separation from the endosperm, on 
suitable media. Of all the host-substances thus tried, cane-sugar has 
by far the greatest nutritive power. Other carbohydrates, as invert- 
sugar, dextrose, levulose, maltose, raffinose, galactose, and glycerol, have 
more or less nutrient value, while milk-sugar and mannitol do not in any 
way contribute to the growth of tissue in the young plant. The authors 
believe that the transformed starch of the endosperm is absorbed by the 
embryo in the form of maltose, and that the seat of the production of 
the cane-sugar which germinated grain contains is the tissues of the 
embryo itself. 
Prof. J. K. Green f has made a series of experiments on the same 
subject in the case of the castor-oil plant ( Bicinus communis ). He finds 
in the resting seeds a ferment or zymogen, which is readily developed 
into an active condition by warmth and weak acids, the results of its 
activity being the splitting up of the oil with formation of glycerin and 
(chiefly) ricinoleic acid. The proteids of the seed, which consist of 
globuline and albumose, are split up by another ferment with formation 
of peptone and asparagin. During the progress of germination there is 
also liberated in the endosperm a rennet-ferment of considerable vigour. 
The author states that the only products which enter the embryo during 
germination are a crystalline acid, sugar, possibly some peptone, and 
asparagin. 
Transformation of the Alkaloids during Germination. :f — From 
observations made chiefly with strychnine, brucine, daturine, and 
* Journ. Chem. Soc., 1890, pp. 458-528 (2 pis.). 
f Proc. Roy. Soc., xlvii. (1890) pp. 146-7. 
X Comptes Rendus, cx. (1890) pp. 88-90. 
