CHANGES IN CELL-ORGANS OF DROSERA ROTUNDIFOLIA. 399 
of Drosera dichotoma as without cuticle, and Goebel! to 
say that the apical gland-cells are not cuticularised. Like 
those of Drosera rotundifolia, the gland is covered with 
cuticle. After prolonged treatment by iodine and sulphuric 
acid all that is left undestroyed of the median longitudinal 
section of a gland of either of these species is the continuous 
outline of cuticle and the cuticularised walls of the third layer 
of gland-cells. 
A method for readily seeing the cuticular envelope in com- 
paratively large pieces is to take an entire leaf that has been 
blanched in alcohol, to soak it in water, then to leave it for 
some minutes in strong iodine solution, to lift it out and wash 
off the superfluous iodine in water. A few of the tentacles 
should then be cut off and laid upon a glass slip; a drop of 
concentrated sulphuric acid be placed upon them, and a cover- 
glass laid over them; and when the reagent is seen through the 
microscope to have taken effect by the usual coloration being 
produced, the cover-glass is to be pressed gently so as to rup- 
ture the apices of the gland and squeeze out the contents. 
The cuticular envelope of the gland usually remains attached 
at its base, and floats out as a semi-transparent membrane 
stained yellow by the iodine. 
Gardiner? describes the gland-cells as “ remarkably pitted 
on their upper or free surface; and Goebel® states that the 
outer walls of the apical gland-cells are dotted. I have exa- 
mined pieces of cuticle obtained in the manner just described, 
with a 1/12 apochromatic oil immersion object-glass by Zeiss 
with oculars Nos. 8 and 12, but have found no well-defined 
pores. I have equally failed on examining sections. The 
internal cellulose protuberances of the thickened outer walls 
of the lateral cells of the external glandular layer often produce 
the appearance of enclosing large deep pits; but it is a decep- 
tive appearance, as a little careful study shows. There is no 
1 Goebel, ‘ Pflanzenbiologische Schilderungen,’ Theil i, p. 198. 
2 Gardiner, W., “On the Phenomena accompanying Stimulation of the 
Gland-cells of Drosera dichotoma,” ‘ Proc. Roy. Soc. London,’ 1885, 
3 Goebel, ‘ Pflanzenbiologische Schilderungen,’ Theil i. 
