Mr. J. Miers on the Calyceracese. 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 Calyceracece 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 n 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 

 laminae, 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 laminse 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 (Linnsea, 



