286 Ewart. — On the Leaf-glands of 
nature. But at no stage could I find starch-granules in the 
cells ; and therefore I conclude, as sugar in some form is 
present in the secretion, it is, as Acton says 1 , c not formed 
by hydrolysis of a carbohydrate.’ He compares its formation 
with that of cellulose from microsomata, and starch from 
amyloplasts in its general nature, but mentions that this is 
not capable of direct proof, on account of the solubility of 
the sugar. 
Treatment with ferrous sulphate, &c., gave an abundant 
tannin-reaction, and with one per cent, osmic acid solution 
the cells became a dark blue colour. But since the cells were 
also darkened with osmic acid after remaining some time in 
ether, it would appear that the coloration is due to the 
presence of tannin, and not of oil. This was confirmed by 
negative results with alkannin. With an ammoniacal solution 
of Cu S 0 4 the whole of the secretory cells became bright 
lemon-yellow, and the same result was obtained with cold 
Fehling’s solution. On heating the slide, or dropping boiling 
Fehling’s solution on to the sections, no alteration could be 
obtained in the colour ; and since tannins will also reduce 
CuS0 4 and Fehling’s solution, I was unable to conclusively 
prove the presence of sugar in the cells. With chlor.-zinc-iod. 
the whole of the gland-cells became a bright yellow, the 
lateral walls of the polygonal cells below the secretory 
epithelium staining a dark orange, and the outer cell-walls 
of the epidermal lips of the duct also showing a marked 
cuticularization. The free cell-walls of the secretory epi- 
thelium were very thin, but appeared to have a yellow, not 
a violet reaction. 
I could find no rupture of the outer cell-walls bordering 
the gland-cavity, and no breaking down into mucilage, and 
therefore conclude that the secretion is forced through the 
cell-wall in some way by the protoplasm of the cell itself. 
The parenchymatous cells surrounding the gland are furnished 
with very large pits in their cellulose walls, and only five 
1 On the formation of sugars in the septal glands of Narcissus. Annals of 
Botany, Vol. ii. No. V. 1888. 
