DR. M. T. MASTERS ON THE PASSIFLORACE E. 613 
directed upwards. When a section is made through such a gland, the following appear- 
ances are presented from above downwards. Two layers of cubical, thick-walled epi- 
dermal cells, ordinary parenchyma, spiral vessels, more parenchyma, and below a single 
layer of epidermal cells. 
Peduncle.—The structure of the peduncle is precisely similar to that of the tendril. At 
the upper part the woody bundles, which below form an incomplete ring, are approxi- 
mated so as to form a continuous vascular circle. As the vessels pass upwards into the 
flower-tube, the bundles are so arranged as to form on transverse section a pentagonal 
outline, a disposition maintained throughout the whole length of the gynophore, as far 
as the point where the stamens are given off. Coupling this fact with the manner in 
which the stamens and gynophore are respectively developed, as before explained, the 
inaccuracy of the statement made in some descriptive works, to the effect that the 
stamens are adherent to the gynophore, becomes obvious. Above the point of emergence 
of the stamens the vessels are arranged in such a manner as to form,.in transverse sec- 
tion, a triangular outline—a circumstance which, as it appears to me, militates against 
Schleiden's notion that theaxis in Passiflora has direct concern in the formation of the 
ovary. 
Flower-tube.—A longitudinal section of the receptacular tube of Passiflora alata shows, 
going from without inwards, an epidermis of thick-walled cubical cells, enclosing paren- 
chyma of large oblong cells containing a little chlorophyll. This parenchyma is tra- 
versed by bundles of spiral vessels, slender wood-cells, and vase proprie. The epidermis 
in the interior of the tube presents a different character according to its position; thus 
in the upper portion, above the median or membranous corona (operculum), it has the 
ordinary characteristics, while below, in the nectary proper, it consists of a number of 
raised papilliform cells, immediately beneath which run af intervals solitary and very 
small spiral vessels. 
Sepals.— The sepals on their lower or outer surface are covered by an epidermis, the 
cells of which are somewhat cuboidal, but sinuous in outline above, and thickened on 
their upper wall. They are interrupted here and there by oval stomata, bounded by two 
sausage-shaped guard-cells containing chlorophyll, a substance not met with in most of 
the other epidermal cells. The inner or upper epiderm of the sepals is of a similar cha- 
racter, and is likewise perforated by stomata. Some of these stomata are of an imper- 
feet character, in that the separation into two guard-cells does not take place. The 
form of the aperture remains unaffected; but it is bounded by a single cell instead of by 
two. 
According to Von Mohl, the stomata originate from the subdivision of a single cell, 
each of the subdivisions becoming a guard-cell. In the imperfect stoma above described 
there has been an arrest of development, as it were, and the sphincter of the stoma is 
formed of one cell instead of by a pair. Charles Morren*, who was the first to notice this 
condition of the stomata, mentions the existence in Passiflora quadrangularis of still more 
imperfect stomata on the calyx, consisting merely of one semilunar guard-cell, as if the 
fellow cell were suppressed. Morren states that he saw, in one case, an aperture, as of 
; * Dodonæa, part ii. p. 18. 
