ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
485 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
Anatomy of Plants.* * * § — In connection with a plan for forming col- 
lections, at the People’s Palace at Brussels, for the popular elucidation 
of the different branches of Natural Science, M. A. Gravis has published 
a useful summary of the general facts connected with the anatomy of 
plants, with regard both to the structure of tissues and to their arrange- 
ment in the different organs. 
Wiesner’s Anatomy and Organography.f — In the most recently 
published part of the new edition of Prof. J. Wiesner’s ‘ Anatomy and 
Physiology of Plants ’ he describes the newest researches on starch, 
chromatophores, plastids, cell-division, structure of the leaf and stem, 
absorption of fluid nutriment, movements of gases, influence of external 
forces on growth, movements connected with growth, &c. The sections 
on cell-division and secretion are new. The difficult questions relating 
to the anatomical changes during the growth of the stem, the connection 
between the anatomical structure and the physiological function of the 
stem and of the root are treated with great detail and clearness. In the 
volume on Organography and Classification a large portion is devoted 
to the sources of medicinal drugs. 
(1) Cell-structure and Protoplasm. 
Hygroscopic Swelling and Shrinking of Vegetable Membranes.^ — 
Herr C. Steinbrinck treats this subject from a mathematical and from an 
empirical point of view, and offers an explanation of various phenomena 
connected with swelling, especially of those which have to do with tor- 
sions. He discusses also the various hypotheses on the constitution of the 
vegetable cell- wall, and gives his adhesion to Nageli’s micellar theory. 
(2) Other Cell-contents (including- Secretions). 
Distribution of Starch at different periods of the year in woody 
plants.§ — From a series of experiments made, especially on different 
species of Conifers, M. E. Mer finds the amount of starch in the leaves 
to be subject to a law of periodicity, and contests the ordinary view that 
the reserve-tissues of woody plants contain a large supply of starch 
throughout the winter. On the contrary, while, about the middle of 
October, the cortex, the phloem, and the xylem are, in general, filled 
with starch in all the organs, a month later it has almost entirely dis- 
appeared from the cortex and the phloem; and in another month this 
disappearance has advanced still further. The medullary rays are first 
* CR. Soc. Roy. Bot. Belgique, xxx. (1891) pp. 8-23. 
f ‘ Elemente d. Wiss. Bot. I. Anat. u. Phys d. Pflanzen, 3. Aufl. (158 figs.). 
II. Organ, u. Syst. d. Pflanzen, 2. Aufl. (270 figs.),’ Wien, 1890 and 1891. See Bot. 
Centralbl., xlv. (1891; p. 213. 
X ‘ Zur Theorie d. hygroskopischen Flachenquellung u. -schrumpfung veg. Mem- 
branen,’ Bonn, 1891, 128 pp. and 3 pis. See Bot. Centralbl., xlvi. (1891) p. 107. 
§ Comptes Rendus, cxii. (1891) pp. 248-51, 964-6. 
