428 Macfarlane . — Observations on Pitcher ed 
each stoma has one guard-cell hid from view, along with the 
stomatic orifice, by the excrescent and parallel position of the 
outer cell. Each excrescence is therefore a stoma so placed 
that one of its guard-cells protrudes next the observer, while 
the other is pushed inwards. It at once occurred to me that 
the conducting surface seen in many Nepenthes might repre- 
sent a water-stomatic region, and by inspection of undisturbed 
pitchers at different hours of the day I found that a con- 
siderable supply of liquid exuded from large pitchers with 
deep conducting areas, such as N. khasyana , &c. The 
amount was greatest in the morning, to judge from the size 
and number of exuded drops. Now Griffith 1 and Hooker 2 
have likened the pitcher of Nepenthes to an enormously 
developed terminal water-gland of a leaf, and the conditions 
now indicated verify this. I hope in time to conduct experi- 
ments on the excretion o( water, as the possibility presents 
itself of these modified stomata being the source of most of 
the liquid found in the pitchers. 
(d) Glandular modifications of the Epidermis . These I will 
speak of according to their position and use, as (1) alluring 
stem-glands, and (2) alluring leaf-glands, both secreting 
a sweet juice intended to decoy insects to the pitcher-orifice ; 
(3) attractive lid-glands, and (4) attractive marginal-glands, 
both exuding a sweet juice, the latter particularly relished 
by insects, and so placed as to induce them to step on to the 
inner pitcher-surface ; (5) digestive glands, which, as already 
pointed out, may either be spread over the whole interior, 
or be restricted to the lower part of it. 
Alluring stem - and leaf -glands. These in their simplest 
condition are composed of a flat layer of columnar epidermal 
cells, with clear protoplasmic contents, and two subjacent 
layers of angular epidermal cells, lying upon two layers of 
clear bead-like cells, beneath which the terminal cells of the 
vascular bundle end (Plate XX, Fig. 13). In the growth of 
three sets of seedling plants that I have examined, these 
1 Posth. Papers, Vol. ii, p. 77. 
2 Trans. Linn. Soc. Vol. xxii, pp. 415-424. 
