compare the following: Iris, figwort, wild yam,
catalpa, trumpet-creeper, centauria, mulleins, foxglove,
beardtongue, and many other fruits.

28. Large pods with small seeds to escape from small holes.--The large
ripe pod of the poppy stands erect on a stiff stem, with a number
of small openings near the top. The seeds are nearly spherical, and
escape, a few at a time, when the stem is shaken by the wind or some
animal, thus holding a reserve for a change of conditions. Here is
an illustration of ripe pods of a bellflower, _Campanula turbinata_,
nodding instead of erect.

[Illustration: FIG. 34.--Ripe pod of poppy on an erect, stiff stem,
ready for wind or animal to shake out a few seeds at the top.]

[Illustration: FIG. 35.--Ripe pods of bellflower bent over; the holes
opening when dry to allow seeds to be shaken out.]

The small holes are still uppermost, but to be uppermost in this case
it is necessary for them to be at the base of the pod.

29. Seeds kept dry by an umbrella growing over them.--When mature,
the apple of Peru, _Nicandra_, keeps every dry bursting fruit covered
with a hood, umbrella, or shed, so that seeds may be kept continually
dry and may be spread with every shake by the wind, or by an animal,
in rainy weather as well as in dry.

In the words of Dr. Gray, "The fruit is a globular dry berry, enclosed
by a five-parted, bladdery inflated calyx." The margins of the lobes
of the calyx curl upwards and outwards as the berry hangs with the
apex downward.

[Illustration: FIG. 36.--Mature fruit of apple of Peru covered by
an enlarged calyx.]

[Illustration: FIG. 37.--The same with the calyx removed.]

[Illustration: FIG. 38.--The same as Fig. 37, except that it is older
and somewhat changed.]

The berry is as large as one's thumb, and when ripe, bursts open
irregularly on the upper side as it hangs up under the calyx. As the
covering of the pod opens more and more, a few seeds at a time may
be rattled out by wind or animal. The numerous large and light fruits,
with calyx surrounding them, are each supported on a nodding stem,
stiff and elastic, which gives the wind a good chance to sway them
about. Water does not seem to get into the berries even when they
are torn open, for when it is poured over the branches it rolls off
the calyx roof as freely as from a duck's back. The fruits of
_Physalis_ are apparently kept dry in a manner similar to the apple
of Peru, although when first mature they are