546 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Anatomy, Morphology and Biology of Cactacese.* * * § — Mr. W. F. 
Ganong enters into further details respecting the structure of this order, 
which is phylogenetically very new and is practically entirely American, 
consisting of about 1000 badly defined species, grouped in about 20 worse 
defined genera. The special characteristics of ths tissues are a strong 
cuticle, thick epiderm, perfect cork, sunken stomites, collenchymatous 
hypoderm, deep palisade-layers, great development of pith and cortex, 
which consist of large round pitted water-storing cells, often containing 
mucilage, and a generally simple fibro-vascular system, the xylem-portion 
composed of annular and spiral tracheids, often collected into gland-like 
masses, the whole system conforming closely to the external form and 
following its morphological changes. 
Comparative Anatomy of the Dilleniaceae.f — Herr H. Steppuhn 
enters into detail as to the structure of the vegetative organs in this 
order, and their value for the purpose of classifying the genera. The 
anatomical structure is remarkably constant throughout the order, and 
shows a close affinity with the Ranunculacese. Some species, which 
are aquatic climbers, are characterized by having vessels of enormous 
size. 
Anatomy of Cyperacese.J — Herr M. Rikli has investigated the 
anatomical structure of the stem and leaf in 24 genera of Cyperacese 
belonging to the Scirpoideas. He lays great stress, both from a structural 
and from a systematic point of view, on the presence or absence of an 
inner parenchyme-sheath to the vascular bundles ; this sheath consists 
of a single clilorophyllous layer of assimilating cells within the pro- 
tecting sheath of the bundle. When this layer is present, the outer 
non-clilorophyllous parenchyme-sheath is nearly always wanting. The 
author proposes to divide the Scirpoidese into two suborders, the Chloro- 
cyperacese and the Eucyperaceye, dependent on the presence or absence 
of this sheath. The three large genera Scirpus, Cyperus , and Heleocharis 
must each be divided into two, according as the species possess or are 
destitute of this sheath ; all the remaining genera fail into one or other 
of the suborders. The stem and leaf are not sharply distinguished from 
one another in the Cyperacese, the two organs being connected by a 
series of intermediate structures. The Chlorocyperacese have two kinds 
of vascular bundle, with round and with oval transverse section, the 
two kinds differing also in their anatomical structure. 
(4) Structure of Organs. 
Amphicarpy of Fleurya.§ — In a species of Urticacese from forests 
in western tropical Africa, Fleurya podocarpa , Herr A. Engler describes 
the phenomenon of amphicarpy. The plant bears two kinds of fruit, 
the one ripening beneath, the other above the surface of the soil, but 
differs from all other known geocarpic and amphicarpic species in 
having only unisexual flowers. The subterranean female flowers differ 
* Bot. Gazette, xx. (1895) pp. 129-38, 213-21 (2 pis.). Cf. this Journal, ante , 
p. 69. 
f Bot. Centralbl., lxii. (1895) pp. 337-42, 369-78, 401-13 (2 pis.) 
% Jahrb. f. wise. Bot. (Pt'effer u. Strasbur^er), xxvii. (1895) pp. 485-580 (2 pis.). 
§ SB. K. Preuss. Akad. Wiss. Berlin, 1895, pp. 57-66 (1 pi.). 
