398 LILY HUIE. 
core of the head, and varying in number with the size and 
vigour of the leaf, and in the centre of which terminates a 
fibro-vascular bundle (consisting of one or two spiral vessels, 
of small lumen, and an accompanying sheath of long narrow 
starch-containing cells) which springs from the vascular 
system of the leaf, and traverses the stalk of the tentacle. 
These non-glandular elements presumably function as a 
channel for the transference of fluids. 
The glandular elements consist of three bell-shaped layers 
of gland-cells covering the tracheids. The external layer is 
composed of cells of two kinds. Those at the apex are thin- 
walled elongated cells, numbering in a longitudinal section 
12—14. The lateral cells of the outer layer are shorter, and 
possess thick walls. Their external walls have tooth-like in- 
ternal projections of cellulose. 
The cells of the second glandular layer resemble closely the 
lateral cells of the superficial layer, but their walls have no 
projections. 
The third layer is composed of comparatively few, but very 
long cells, which are remarkable for the large amount of 
tannin in solution contained in their cell-sap, and for the 
strong cuticularisation of those walls, both longitudinal and 
transverse, which separate them from one another. The 
transverse walls are worthy of special attention, because they 
are composed of two projections, one from each side. The 
projection from the outer side is strongly cuticularised ; that 
from the inner side (next the tracheids) is lignified. Between 
the two there is a minute space through which intercellular 
communication is permitted. This layer of cells is also epi- 
dermal in its origin, and arises from a zone of epidermal cells 
immediately below that forming the initial cells of the lateral 
external layer. Hach cell of this zone elongates inwards and 
then subdivides. 
The entire tentacle head is cuticularised superficially. I do 
not understand how Gardiner’ comes to describe the glands 
1 Gardiner, W., ‘On the Phenomena accompanying Stimulation in the 
Gland-cells of Drosera dichotoma,” ‘Proc. Roy. Soc. London,’ 1885. 
