390 LILY HUIE. 
the same attraction for water as the remaining contents of the 
vacuole, but possesses a different chemical composition. The 
colouring-matter, the tannin, and certain unknown albumins, 
precipitable by ammonium salts, are retained inside the vacuole. 
The grape-sugar and vegetable acids are probably, in part at 
least, expelled. ‘l'urgor is almost the same in stimulated as 
in unstimulated tentacles; it takes, e.g., a solution of between 
2 per cent. and 3 per cent. KNO, to produce plasmolysis in 
unstimulated tentacles. The author finds that aggregation 
takes place first in the cells nearest the glands, and that divi- 
sion of the vacuoles occurs also in the gland-cells themselves, 
although no protoplasmic circulation is to be seen. When 
stimulation ceases the cells return gradually to their original 
condition, while the vacuoles increase in size, and ultimately 
fuse again into a single one. 
This author describes further a similar but distinct pheno- 
menon. Under certain conditions, especially when stimulated 
by salts of ammonia, by free ammonia in weak solution, by 
iodine, by osmic acid, and even sometimes by stimulating a 
fresh leaf with albumin, or by slowly killing a tentacle , by 
drying, the albumins dissolved in the sap of the vacuole are 
precipitated; first in the form of a fine granulation, afterwards 
fusing into larger globules equalling in size the little vacuoles 
formed by aggregation, when it is not easy to distinguish be- 
tween this appearance and that resulting from aggregation. 
But that they are different phenomena may be shown by first 
inducing normal aggregation, and then treating the aggregated 
cells with 1 per cent. ammonium carbonate. 
The ammonia salts did not penetrate the thick cuticle of the 
tentacle stalks, but entered at the cut places and also by the 
gland-cells of the tentacle, and the little mammilla-shaped 
glands situated on the stalk of the tentacle. 
A year previous to the appearance of De Vries’ papers, 
Gardiner! published an account of “The Phenomena accom- 
1 Gardiner, W., “On the Phenomena accompanying Stimulation in the 
Gland-cells of Drosera dichotoma,” ‘Proc. Roy. Soc, London,’ 1885, 
p. 229. 
