1895.] Botany. 847 
The work was divided into an elementary and an advanced course, 
the former for those who took up the study of botany for the first time, 
and the latter for those who had already made some progress in the 
study. The attendance was large, considerably exceeding one hun- 
dred, and was composed almost entirely of teachers of maturer years, 
in all departments of school work, from the kindergarten to the high- 
school and academy.—CuaRr.es E. Bessey. 
VEGETABLE PHYSIOLOGY’ 
Fischer on Bacteria.—Under the title Untersuchungen ueber 
Bakterien, Dr. Albert Fischer contributes an important paper to a re- 
cent number of Pringsheim’s Jahrbücher fur wissenschaftliche Botanik 
(Bd. 27, H. 1, pp. 163, T. 5, Berlin, 1895). This paper consists of four 
parts: (1) New observations on the plasmolysis of bacteria; (2) The 
physiology of the flagella and of the movement; (3) The morphology 
of the flagella; (4) Classification. Of the five plates illustrating fla- 
gella, four are lithographic, and one is a collotype. The author ap- 
pears to have made out pretty clearly for a good many forms that the 
contents of the bacterial cell is plasmolyzed even by a slight concentra- 
tion of culture media such as takes place on the cover glass in drying 
or in the transfer of the organisms from a weaker to a more concentrated 
culture medium. This plasmolysis can be avoided by diluting the fluid 
very plentifully with water before making cover glass preparations 
from it. Only a very slight amount of sodium chloride is necessary to 
produce plasmolysis of a cover glass preparation, especially at the edge 
of the drop, viz.: 0.01 to 0.05 per cent. The occurrence of this phe- 
nomenon can be observed in a hanging drop as it dries. Plasmolysis 
disappears when watery stains are used, but is beautifully preserved by 
alcoholic stains, Ziehl’s carbol fuchsin, or Delafield’s haematoxylin. 
Many false conclusions have been drawn from such plasmolyzed bac- 
teria. Here belong De Toni and Trevisan’s genera Pasteurella and 
Dicoccia ; the staining phenomena of the cholera vibrio, described by 
Rahmer ; the bamboo-like joints sometimes seen in the anthrax bacil- 
lus ; the polar bodies in the typhoid bacillus; the various granular 
structures in the tubercle bacillus, etc. The unstained, empty places 
1This department is edited by Erwin F. Smith, Department of Agriculture, 
Washington, D. C 
58 
