420: The Botanical Gazette. [September, 
drop containing the bacteria undergoes a concentration of sa- 
line material sufficient to induce plasmolytic action. The 
lacune and uncolored areas so often noted in many different 
species of bacteria, when stained indicate where the proto- 
plasm has shrunken from the limiting membrane under the 
action of the salt solutions. In certain instances plasmolyzed 
preparations recovered their turgor by the permeation of the 
salt solution into the bacterial cell. The protoplasm of the 
same species, however, is not permeable to different salts in 
an equal degree. : 
The importance of these observations on plasmolysis are 
considerable, as they have a direct bearing on the theory of 
the nature of the bacterial cell. 
elements are represented, and also with reference to plasmo- 
lytic action. 
II. The view has been advanced that the cilia of swarm 
spores of different plants, and also bacteria, are protoplasmic 
processes that are extruded from the main part of the cell 
through minute Openings in the limiting membrane, and that 
these filiform appendages are capable of being withdrawn en- 
tirely within the cell proper. If this were so, plasmolyzed 
bacterial cells would hardly be expected to show any appre- 
ciable degree of motility, yet, a number of different motile 
forms plasmolyzed in weak solutions (2.5 per cent. KNO;, 
1.25 per cent. NaCl), showed no cessation of movement. If 
strong solutions were used, motion ceased immediately. This 
was not, however, on account of the retraction of the cilia, 
but a rigor caused by the concentration of the solution. 
f The addition of disinfectants (carbolic acid, 0.1 per cent.) 
in Proportions insufficient to cause a cessation in develop- 
ment, likewise sufficed to produce a similar state of rigor. 
 ®Bau der Bakterien. 1890. 
