SUMMARY OF CURRENT RESEARCHES RELATING TO 
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BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-structure and Protoplasm. 
Nucleus and Formation of Membrane in Fungi and Myxo- 
mycetes.* — According to Herr F. Rosen there are three different ways 
in which division of the nucleus and cell-division may take place, un- 
connected with one another, viz.: — (1) Cell-division takes place inde- 
pendently of the nuclei, or at least of its divisions ( Cladojpliora ) ; 
(2) Division of the nucleus takes place without any following cell- 
division ; and either (a) the cell no longer divides, while the number of 
nuclei increases, or ( b ) the multiplication of nuclei partakes of the 
character of a pathological phenomenon, or is the result of external 
forces. The last case, which is very common in the animal kingdom, 
has been observed in plants in parasitic infection, especially in the 
formation of galls ; and in callus. 
After detailing the observations which have been made on the mode 
of nuclear division in the Fungi and Myxomycetes, the author thus 
sums up the more important conclusions. In no case hitherto observed 
does the division of the nucleus in Fungi partake altogether of the 
character of indirect division ; the process is, on the other hand, always 
simpler than in the higher plants. Only in Tricilia and in the Exoasceae 
has a typical achromatic figure been distinctly seen. The division of 
the chromatic elements or nuclear filaments is never effected by longi- 
tudinal fission. The simplification cannot be regarded as simply a 
result of the small size of the nuclei, since the greatest abnormalities 
have been observed in Synchytrium Taraxaci, where the nuclei are the 
largest. But, as a general rule, the smaller the nuclei, the more simple 
is their mode of division. In the smallest of all nothing can be detected 
but an appearance of chromatic granules, followed by a division into 
two groups which constitute new nuclei. In some Myxomycetes the 
nucleus takes part in the formation of membrane, not, however, in its 
first appearance, but in its further development. The author confirms 
the main points of Sachs’s statement f with regard to the part played 
by energids in the vital processes within the cell. 
Streaming of Protoplasm.^;— Herr P. Hauptfleisch distinguishes three 
kinds of movement of the protoplasm in cells invested with a cell-wall : 
— an irregular circulation in the meshes of the albuminous network, 
corresponding to the streaming of protoplasm in naked plasmodes ; a 
rotation along the walls of the cell ; and an oscillatory movement of the 
particles, resembling that known as the brownian movement. All these 
movements belong only to cells of a certain age, after vacuolation has 
commenced ; in the movement of rotation all the organized elements 
* Beitr. z. Biol. d. Pflauzen (Cohn), vi. (1892) pp. 237-66 (2 pis.). 
t Cf. this Journal, 1892, p. 381. 
% Jahrb. f. Wiss. Bot. (Pringsheim), xxiv. (1892) pp. 173-234. 
