ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
207 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
Tschirch’s Text-book of Anatomy.* — This volume, which serves as 
an introduction to a general work on Economical Vegetable Anatomy, 
embraces a discussion of the following subjects : — Structure of the cell, 
cell-contents, and reagents, including aleurone, chlorophyll, chromoplasts, 
fatty oils, starch and starch-generators, calcium oxalate, tannins, alka- 
loids, essential oils and resins, glucosides, &c. ; formation and growth 
of the cell-wall, including a discussion of the so-called “ intercellular 
substance ” ; different tissue-systems, adopting Haberlandt’s classification ; 
and a detailed account of secretion-receptacles. 
(1) Cell-structure and Protoplasm. 
Elementary Structures and Growth of the Vegetable Cell.f — Prof. 
J. Wiesner maintains that, since the cell-contents, such as chlorophyll- 
grains, &c., assimilate, grow, and multiply by division, the cell cannot 
be the ultimate elementary structure of the plant ; it must inclose a 
number of simpler living structures, and may possibly consist of an 
organic combination of such structures. It is exceedingly probable 
that the protoplasm is itself made up of such elementary structures ; 
it is itself organized, and, with its organized contents, nucleus, 
chlorophyll-grains, &c., can only multiply by division. For these living 
elements of the protoplasm which he formerly called plasmatosomes,J 
the author now proposes the simpler term plasomes. 
Among the different kinds of plasome are to be reckoned the 
protoplasmic rudiments from which originate the chlorophyll-grains, 
the starch-grains, the vacuoles, the tannin-vesicles, aud other similar 
structures, as well as the rudimentary structures from which the derma- 
tosomes of the cell- wall are formed. The plasomes differ from one 
another as the cells of a tissue differ from one another ; and they bear 
the same relation to the cell as the cells do to the tissue. Like certain 
cells, the plasomes appear to possess the property of uniting with one 
another, or of elongating into fibrils ; or they may disappear by absorp- 
tion. 
In the lowest known organisms, such as the lower Schizophyta, the 
plasomes do not develope into separable products ; in the lower Fungi, 
such as Saccharomyces, there are formed within the cell, from the 
plasomes, simply vacuoles and rudimentary nuclei, and the plasomes 
which constitute the cell-wall are so small that they cannot be recognized 
as dermatosomes. From the Algae upwards the most various substances 
are formed out of the plasomes, but even in the highest plants all the 
* ‘ Angewandte Pflanzen-anatomie : Bd. 1, Grundriss d. Anatomie,’ 8vo, Wien u. 
Leipzig, 1890, xii. and 548 pp., 614 figs. 
t SB. K. Akad. Wiss. Wien, xcix. (1890) pp. 383-9, and Ber. Deutsch. Bot. 
Gesell., viii. (1890) pp. 196-201. 
X Cf. this Journal, 1886, p. 818. 
