308 TRANSVERSE AND POROUS DEHISCENCE, 
lower adherent one, so that it would appear as if the adherence 
of the calyx had some effect in this case in producing the 
transverse dehiscence. Such fruits are sometimes called oper- 
culate, a term which is also applied by other botanists to all 
forms of transverse dehiscence in 
Fic. 685. Frc. 686. Which the upper portion of the peri- 
carp separates from the lower in the 
form of a lid or operculum. 
Transverse dehiscence may also 
occur in fruits which are formed by 
a single ovary or carpel, as well as 
in the compound ones mentioned 
above. Thus, the legumes of Coro- 
villa, Hedysarum (fig. 686), Orni- 
thopus, &c., separate when ripe into 
as many portions as there are seeds. 
The separation taking place in these 
cases has been supposed to be ef- 
edt hal ae fected by a process called solubility. 
eheeeedea for Some botanists regard such legumes 
tions. as formed of folded pinnate carpel- 
. lary leaves analogous to the ordinary 
pinnate leaves of the same plants, the divisions taking place at 
the points of union of the different pairs of pinne. 
3. Porous Drniscence.—This is an irregular kind of dehis- 
cence, in which the fruits open by little pores or slits formed in 
Fig. 685. Pyxis of 
the Monkey-pot 
(Lecythis ollavia). 
Fig. 686. Lo- 
mentum of a 
species of Hedy- 
sarum separating 
Lire (etel7/ Fic. 688. 
Fig. 687. Immature fruit of a speciesof Campanula. p. Pericarp. 7¢, t. Pores 
at the sides. c¢,c. Persistent calyx united below to the wall of the fruit 
so as to form a part of the pericarp. Fig. 688. Fruit of a species of , 
Campanula dehiscing by pores at its base. 
their pericarps by a process called rupturing. These openings 
may be either situated at the apex, side, or base of the fruit, 
hence they are described accordingly, as aprcular, lateral, or 
basilar, Examples of this kind of dehiscence occur in the 
