6 
CONTRIBUTIONS TO BOTANY. 
The seed in Nastanthus is deeply 5-grooved, its salient lobes 
corresponding to and continuous with the round and concave 
teeth of the calyx. If we make a transverse section across 
the achsenium, we find in the bottom of these grooves no meso- 
carpic space between the thin endocarp and epicarp; so that 
the external diameter of the seed in that part httle exceeds that 
of the apical tubercle; but the salient lobes or wings, which 
extend from the calycine teeth to the base, are often more than 
thrice that diameter; and the space between the epicarp and 
endocarp in these wings is filled with a pithy medulla, no trace 
of which exists in the intervals of the grooves. There are seen 
in this section ten very distinct longitudinal nerves upon the 
endocarp, five of which are opposite the grooves, the other five 
being alternately placed opposite the wings, all of them at equal 
distances : in the longitudinal section these ten nerves are seen 
to run parallel to one another from the base to the apex, and to 
pass through the apical tubercle, forming the intermediate fibrous 
stratum above mentioned. At the summit they all seem com- 
bined in a plexus, whence are thrown out the nourishing threads 
to the placental cord for the support of the ovule and for the 
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 
wnth ten parallel neryures, 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 runs parallel with each margin of the segments, and all 
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 flve 
■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 eveiy two segments; but, though 
