DR. M. T. MASTERS ON THE PASSIFLORACE X. 597 
question. Others might possibly object to the term “ receptacular tube,” a denomination 
which appears to the writer to be correct, from the conformation, structure, and mode of 
development, as well as from the consideration of the nature and number of the parts 
that are attached to, or rather which emerge from it. These are points which will 
receive further comment under other headings. Looked at as a means of discriminating 
species, the flower-tube presents valuable ‘characters.’ Its form, consistence, and size 
are all subject to variation in different species: thus it is flat and saucer-shaped, or bell- 
shaped, or tubular, or funnel-shaped, and so on; thin and membranous, or thick and 
fleshy; sometimes rounded at the base, in other species umbilicate, from the excessive 
growth of some portions as contrasted with others. The phrase so often made use of in 
describing these plants (tubus basi intrusus) must be taken conventionally, and, not 
literally. ‘Bes y 
Calyx-lobes. Sepals.—These are usually five in number, quincuncially imbricated in 
the bud, and so placed that two are anterior or nearly so in relation to the axis that 
bears them, two lateral, and one posterior. They are almost invariably vaginal in their 
venation (multicostate, convergent); but not unfrequently they present a trace of a petiole, 
in the shape of a small horn-like projection from the upper end of the dorsal surface, just 
below the apex. They are often thick in substance, except at the margins, which fre- 
quently retain the traces of the overlapping that occurs in the bud in their thinner 
. texture and petaloid coloration; thus the two sepals that are overlapped on both sides 
by the edges of the adjoining sepals have their margins thin and petaloid, while those 
sepals which are only overlapped on one edge have one thin margin only. 
Corolla.—' The petals are occasionally wanting, but more generally they are present, 
and originate, with the sepals, from the upper edge of the flower-tube, within and 
alternately with the calyx-lobes. In the bud they are quincuncially imbricated, one of 
the petals being completely external, one completely internal, and the remainder partly 
external, partly internal. "They are usually multicostate ; but in Paropsia each petal has 
a single costa. | 
The petals are usually equal in size and regular in form; but in a genus (Atheranthera) 
of which a description and illustrations will be found further on, and of which only male 
flowers exist in Dr. Welwitsch's collection of Angola plants, the five petals are unequal 
in size, quincuncially imbricated, the two innermost much larger and more concave 
than the rest. This inequality of size is probably not congenital, but manifests itself 
during development. As a consequence, some of the sepals are more widely separated 
one from another than the rest. e 
The calyx and corolla of Ceratiosicyos and Acharia require passing notice, as they have 
been differently described by different authors. In Ceratiosicyos the five sepals are 
spreading, linear, much shorter than the corolla, to the base of which they are adherent, 
The corolla is somewhat bell-shaped, and consists of five united petals. In Acharia there 
are four distinct, ovate, leafy sepals, free from adhesion to the corolla, which latter is 
bell-shaped and gamopetalous. If the female flower of Acharia be examined first, or to 
the exclusion of the male, which is rarer in herbaria, the presence of four small glands, 
opposite to the lobes of the inner bell-shaped part of the flower, is liable to lead the — : 
