Mr. J. Miers on the Calyceracez. 179 
production of the raphe ; while other portions branch off through 
the style and the epigynous disk, thus giving rise to the nervures 
of tracheal vessels destined to assist in the growth of the sta- 
mens, and also furnishing the longitudinal nervures of the 
corolla. We thus perceive the nature and function of the apical 
tubercle, and can well imagine how the corolla falls away at a 
very late period, by a circumscissile line across the plexus, and 
also why it carries away the disk with it. 
In the Calyceracee the segments of the corolla always alter- 
nate with the lobes of the calyx, and the stamens, again, recipro- 
cate with those segments. The tube of the corolla is furnished 
with ten parallel nervures, originating at the base, as above 
described, five running through the median line of the segments 
and terminating in a gland at their apex, the other five alter- 
nating with them, and nearly reaching the angle of each sinus, 
before which they bifurcate and throw off on each side a nervure, 
which run parallel with each margin of the segments, and which 
anastomose with the median nerves at their termination. I have 
mentioned that the “ tubillus,” consisting of the united filaments 
and the disk, though agglutinated below to the tube of the 
corolla, may be separated throughout the whole length of this 
confluence by laceration, when it appears furnished with five 
longitudinal nervures, which run from the base and through the 
free portions of the filaments to the anthers: these nervures are 
therefore opposite to the five shorter nerves of the corolla which 
lead to the sinus between every two segments; but, though 
apparently confounded, they are distinct from them, as shown 
when the “tubillus” is drawn away from the corolla. 
There is a peculiarity of structure in Nastanthus and Anomo- 
carpus, and, in a less degree, in most genera of the family, 
which is most distinctly visible in the polliniferous flowers of 
the two genera just mentioned :—the tube of the corolla and the 
segments of its border appear to consist of two distinct parallel 
laminz, with a vacant space between them, as if the entire sub- 
stance of a very thick mesoderm had disappeared by absorption 
or desiccation, leaving only a small quantity of cellular tissue 
consolidated in the apex of the segments, under the form of a 
glandular callus, which apical callus is a constant feature through- 
out the family. This separation of the two surfaces is greater 
in the segments than in the tube; the outer face is very convex, 
forming a prominent gibbous hood about the inner face, which 
is nearly flat : these two laminz are perfectly united at the edges 
of the segments ; the outer one is very thin, hyaline, reticulated, 
and contains no nervures ; the inner one is more opake, coloured, 
and is furnished with the nervures above described. This struc. 
ture is confirmed by the observation of Dr. Philippi (Linnea, 
