ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
55 
BOTANY. 
A. GENERAL, including' the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-structure and Protoplasm. 
Morphology and Physiology of the Cell.* — The second part of 
Herr A. Ziinmermann’s work on this subject treats of three points, — 
The chromatophores in etiolated leaves; Protein crystalloids; and The 
mechanical explanations of the form and arrangement of the cell- 
membrane. 
Sharply defined chromatophores are more common in the colourless 
parts of bleached leaves than has been supposed ; it is only rarely that 
they are entirely wanting. They vary in all degrees, in size and colour, 
from normal green chloroplasts, the extreme cases being colourless and 
only one-fourth the normal size. In some cases chromatophores were 
found containing vacuoles, and with a nearly normal appearance. The 
formation of starch is always ci nnected with the presence of chromato- 
phores, and invariably takes jdace either in their interior or on their 
surface. This is true even of colourless chromatophores. The mode of 
treatment employed was to inject the leaves, before making sections, with 
a 5 per cent, solution of sugar. The fixing material used was 
corrosive sublimate ; the staining reagent iodine-green aud ammonia- 
fuchsin. 
The protein crystalloids are often of such regular form that their 
crystalline nature cannot be doubted ; but they are often nearly or quite 
spherical, and then their nature can only be determined by staining 
processes. The best reagent for this purpose is acid fuchsin or a double 
staining with acid fuchsin and hsematoxylin ; the latter is a certain test 
for distinguishing crystalloids from nucleoles. In some natural orders, 
such as Oleacese and Scrophulariaceae, crystalloids were detected in al- 
most every species examined. The author was unable to arrive at any 
conclusion as to their function. They are abundant in some parasites 
aud insectivorous plants, while entirely wanting in others. During caryo- 
kinetic division of the nucleus, the crystalloids are forced into the cyto- 
plasm, where they are apparently absorbed, new ones being formed in 
the daughter-nuclei. In many plants crystalloids were found within the 
chloroplasts of the assimilating tissue ; in others even within the epiderm. 
In the Orcliidere the parenchyme of the vascular bundles contains abund- 
ance of crystalloids, as well as roundish bodies contained within the chro- 
matophores, which are probably identical with the leucosomes of Trad.es- 
cantia, and belong to the same category as crystalloids. Crystalloids 
were found in the cytoplasm or the cell-sap in five different plants. 
In the formation of the cell-wall two different processes must be 
distinguished, — the formation of the cell-membrane, and the displace- 
ments which take place during its growth. On the whole, Niigeli’s 
theory of intussusception appears the best adapted to explain the 
complicated phenomena connected with the growth of the cell-wall. 
* Beitr. z. Morph, u. Physiol, d. Pflanzenzelle, Heft ii., 102 pp. and 2 pis., 
Tubingen. See But. Centralbl., xlviii. (1891) p. 182. Cf. this Journal, 1890, p. 617. 
