320 SUMMARY OF CURRENT RESEARCHES RELATING TO 
which includes by far the greater number ; in these the teeth or valves 
exhibit a variety of imbibition or hygroscopic curvatures, according to 
the amount of water they absorb. The mechanical elements may occur 
in one only or in several layers of cells. (B) Capsules splitting by a 
transverse fissure (pyxis). (C) Fruits which do not split or are irregu- 
larly ruptured. 
The variations of structure are then pointed out within each natural 
order ; in some cases a special anatomical character runs through a 
whole group. A very large number of species are specially described 
as far as the capsule is concerned. 
The physiological bearings of the different types of structure of 
capsular fruits are briefly discussed. The imbibition curvatures of the 
walls of the capsule are connected with the dissemination and with the 
protection of the seeds. 
Fruit of Amphicarpaea.* * * § • — Dr. Adeline Schively finds that the 
minute cleistogamic flowers of Amphicarpaea monoica , when buried, 
produce one-seeded nuts with soft fruits and seed-coats ; while the purple 
flowers, if buried in the bud state while still attached to the plant, pro- 
duce perfect underground nuts instead of 3-4-seeded indurated pods. 
Fibrovascular Bundles of Leaves. Pursuing his investigations 
on the number and symmetry of the fibrovascular bundles of the petiole, 
M. A. Chatin states that in Monochlamydese a single bundle is found, 
as a rule, only in the woody species. An affinity is established between 
the Laurinem and the Daphnacese ; wliile the Euphorbiacese are shown 
to have no near affinity to the Malvaceae. The Polygonacese, with their 
sheathing petioles, always multifascicular, correspond, in this sign of 
degradation, with the Ranunculacese among the hypogynous Dialypetalae, 
and the Umbelliferae among the perigynous Dialypetalae. There is no 
corresponding structure in the highest class, the Corolli florae. 
Size of the Leaves of Conifers.} — Following out his studies on this 
subject, Herr R. Meissner states that in Pinus there is an alternate in- 
crease and decrease in the length of the leaves in successive years. 
In other genera the solitary leaves, whether on primary or secondary 
branches, exhibit the same phenomenon. An increase in thickness (es- 
pecially in the sieve-portion), but not in length, takes place in those 
leaves whose activity extends over several years. 
Adventitious Buds on Leaves of Drosera.§ — Mr. A. J. Grout re- 
cords an example of this phenomenon in the case of Prosera rotundifolia, 
several leaves bearing from two to ten young plants on their upper sur- 
face. 
Propagating Roots in Xpomaea.|| — Mr. G. L. Clothier states that 
Ipomsea leptophylla produces propagating roots which originate from 
various points, most abundantly from the lower part of the vertical 
fleshy root. They pass out horizontally for a short distance, then rise 
* Bot. Gazette, xxv. (1898) p. 117. Contrib. Bot. Lab. Univ. Pennsylvania, i. 
(1897) pp. 270-363 (18 pis.). 
f Comptes Rendus, exxvi. (1898) pp. 700-6. Cf. this Journal, ante, p. 210. 
t Bot. Ztg., lv. (1897) l te Abth., pp. 203-18. Cf. this Journal, 1894, p. 472. 
§ Amer. Naturalist, xxiii. (1S98) pp. 114-5 (1 fig.). 
11 Bot. Gazette, xxv. (1898) pp. 52-3 (1 fig.). 
