110 PROF. T. H. HUXLEY ON THE GENTIANS. 
VIII. Ptychanthe. 
The corolla is campanulate or infundibulate, never rotate. 
The wall of the tube, between the interlobular sinuses and the 
insertion of the filaments, is produced into a series of longitu- 
dinal plications or “interlobes,” the folded edges of which pro- 
ject into the throat of the tube, and more or less completely 
divide it into a corresponding number of longitudinal passages. 
. The free margins of the interlobes may extend as far as those of 
the lobes, and they may be provided with long lacinie. In some 
species the anthers cohere into a ring round the style, below the 
stigma, which last may take the form of a disk. Very often, the 
stemono-corolline symphyses are produced into strong longitu- ` 
dinal ridges, which continue the direction of the interlobular 
folds, and, by abutting against the ovary, subdivide the basal 
moiety of the cavity of the flower into passages which continue 
those in its marginal half. The base of the ovary is often tuber- 
culate and clearly nectarigenous. The basal portion of its 
cavity is often devoid of ovules ; and, sometimes, is elongated into 
a narrow stipes, which, in certain cases (e. g. Crawfurdia), attains 
a great length. 
This type of structure is found exclusively in those species of 
the genus Gentiana which are included by Grisebach under the 
heads of Celanthe, Tretorhiza, Cyane, Chondrophyllum, Thylacites ; . 
in some of the Andicola; and in the genus Crawfurdia. 
I have specially examined the following out of the numerous 
species which exhibit this type of structure, several in the fresh 
state :— 
A. B. C. 
Gentiana Gentiana Gentiana 
verna. sedifolia. pedicellata. 
prostrata. prostrata. zeylanica. 
squarrosa. spathacea. Loureirii. 
asclepiadea. adsurgens. 
Andrewsii. ramosissima. 
affinis. Gayi. 
acaulis. 
purpurea, 
Burseri. 
punctata. 
cruciata. 
nikoensis. 
Buergeri. 
Thunbergii. 
japonica. 
Crawfurdia. 
