ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
327 
Leaves of Ranunculus and Heileborus.* — Dr. A. Nestler has made 
a critical examination of the anatomical characters of the leaves in these 
two genera. In Ranunculus the hairs are always unicellular ; water- 
pores occur in all the species, even in the floating and submerged leaves 
of Batracliium. Many species have small crystals of calcium oxalate in 
the epidermal cells ; one only, R. asiaticus, has large crystals in the 
fundamental parenchyme of the leaf-stalk. The two most distinguishing 
features in the leaves of Helleborus are that the sclerenchymatous fibres 
form a completely closed sheath surrounding the vascular bundle ; and 
that they are entirely wanting in the leaf-segments. 
Extrafloral Nectaries of Ficus.f — Sig. M. A. Mirabella describes 
the nectaries found on the leaves of several species of Ficus. They agree 
with one another in their anatomical character, in their origin, which is 
always as modifications of epidermal cells, and in the nature of their 
contents, which consist, in addition to saccharine matters, of proteid 
substances, but not of starch. They make their appearance as small 
areolte, with well-defined outline, somewhat depressed, sometimes covered 
with a white scurf. They are usually situated on the under surface of 
the leaf in the axils of primary veins, less often on the branches at the 
base of a leaf-stalk. 
Hairs of Myristicacese.'l — Herr O. Warburg describes the very 
peculiar trichomes which are characteristic of all the genera of 
Myristicacete examined. The hairs are multicellular, and either one- 
armed or two-armed. In the former case each cell is more or less bent 
at right angles, and springs from the bent angle of the one beneath it. 
In the latter case, each cell is produced in two directions from the point 
from which the next cell above it springs, so that the successive cells 
are greatly elongated in a direction nearly parallel to the surface, and 
each '’is attached nearly by its middle to the one above and to the one 
below it. The number of such cells of which a hair is composed is some- 
times very large. 
Characters of Arceuthobiacese.§ — M. P. Van Tieghem gives ana- 
tomical reasons for the separation of Arceuthobium as a distinct natural 
order, intermediate between Loranthacese and Santalaceae. In the 
Loranthacese the embryo-sacs are directly plunged in the cortex of the 
carpels ; there is neither placenta nor ovules, and therefore no open 
ovarian cavity. In the Arceuthobiaceae there is a placenta and an open 
ovarian cavity, but the embryo-sacs are still completely imbedded in the 
placenta, and there are no ovules. In the Santalaceae there is also a 
placenta in an open ovarian cavity ; but this placenta puts out pro- 
tuberances, in the interior of each of which an embryo-sac is differen- 
tiated, and which are therefore naked ovules. 
Morphology of Limnanthemum.|| — Herr R. Wagner describes in 
detail the structure of the organs of Limnanthemum nymphseoides, an 
aquatic member of the Gentianaceae. 
* Verhandl. K. Leop. Car. Deutsch. Akad. Naturf., lxi. (1894) pp. 1-44 : lxiii. 
(1895) pp. 281-310 (6 pis.). Cf. this Journal, 1893, p. 754. 
f Nuov. Giom. Bot. Ital., ii. (1895) pp. 340-7 (1 pi.). 
X Ber. Deutsch. Bot. Gesell., xiii. (1895) Gen.-Vers.-Heft, pp. 78-81 (1 pi.). 
§ Journ. Soc. Bot. France, xlii. (1896) pp. 625-31. Cf. this Journal, ante, p. 206. 
|| Bot. Ztg., liii. (1895) l te Abth., pp. 189-205 (1 pi.). 
