ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
213 
two guard-cells. Primordial or primary leaves often intervene between 
the cotyledons and the adult foliage-leaves ; and the adult leaves may 
vary in different stages of the plant’s growth or on different parts of its 
branches. The leaves not unfrequently exhibit movements, the purpose 
of which is apparently to secure the exposure of the stomatiferous surface 
to light and heat. The “ needles ” of Pinus are regarded by the author 
as true leaves. The “ needles ” of Sciadojpitys , on the other hand, may 
probably be axial structures. 
Dr. Masters adopts the gymnospermous view of the flowers of the 
Coniferae, and also the hypothesis that each male “ catkin ” is a single 
flower. The number of pollen-sacs in an anther (microsporange) varies 
between two and as many as twenty. The form of the pollen-grain, 
whether winged or not, cannot be used as an absolutely certain character 
to distinguish between the Cupressineac and the Abietineae. In the 
female flower the fruit-scale is almost invariably present as something 
superadded to the bract ; it may arise as an enation either from the base 
of the bract or apparently from the axis just within or above it : its 
structure is neither that of a leaf proper nor that of an ordinary shoot, 
but bears more resemblance to that of a cladode. 
Theory of Pseudanthy.* * * § — Prof. F. Delpino argues that organogeny 
by itself is a very untrustworthy test for determining the morphological 
nature of organs. It is only the comparative morjdiology of the mature 
organ that can determine this. Applying the theory of pseudanthy, 
and in harmony with the evidence afforded by the course of the fibro- 
vascular bundles, as is well shown in Alcsea rosea, he traces the descent 
of the Malvaceae from a type allied to Bicinus , the staminiferous bodies 
of this latter genus having become converted into the staminiferous tube 
of the Malvaceae, Bombaceae, and Sterculiaceae. The Hypericaceae agree 
with the Malvaceae in being pseudanthic, and in all other essential 
points, differing from them only in characters of secondary importance. 
Staminodes of Parnassia.| — From an examination of abnormal 
flowers of Parnassia palustris, Dr. R. von Wettstein draws the conclusion 
that each staminode or nectary represents not a bundle of stamens, but 
a single stamen, the central branch corresponding to the filament, and 
all the branches on each side to an anther-lobe. This conclusion supports 
the view that the Parnassiaceae are related to the Saxifragaceae rather 
than to the Hypericaceae. 
Pollen-grains. if — Herr H. Fischer has examined the structure of 
the pollen-grains in 2214 species of plants. In 1180 of these he finds 
the extine to present three parallel folds. The most complicated struc- 
ture of the extine occurs in the Compositae ; it is much simpler in the 
Monocotyledones than in most Dicotyledones. The author could in no 
case detect the existence of a third membrane. 
Tendrils of the Passifloraceae.§ — M. W. Russell states that there is 
great difference of opinion amongst botanists as to the nature of the 
* Malpighia, iv. (1890) pp. 302-12 (1 pi.). Cf. this Journal, 1890, p. 623. 
f Ber. Deutsch. Bot. Gesell., viii. (1890) pp. 304-9 (1 pi.). 
x Beitr. z. vergleich. Anat. d. Pollen-korner, Breslau, 1890, 69 pp. and 3 pis. 
§ Bull. Soc. Bot. France, xxxvii. (1890) pp. 189-91. 
