x 
done by placing a plasmodium in a saturated aqueous < 
A a OS, E ee N, 
376 The American Naturalist 
BOTANY. 
Protoplasmic Physics.—Prof. Pfeffer, of Leipzig, has publis 
the results of his studies on the taking up and extrusion of soli 
stances by the plasmodia of Myxomycetes, cially of Chondn 
aifforme. He concludes that, contrary to the more generally accey 
the plasmodium. The plasma-membrane closes behind the inclu 
object like a film of oil from which a needle is withdrawn. “a 
Indifferent or insoluble substances are not infrequently enclosed 
vacuoles, from which they may pass back into the protoplasm ; È 
vement, Itis, as yet, wholly impossible to explain why one 
follows the movements of the protoplasm, while others are thro ut 
In the study of protoplasm within the cell-wall the author observed in the 
root-hairs of Zrianea bogotensis that precipitates formed in the 
modia of Chondroderma, he has observed all the intermediate conc i 
betwee pulsating and inactive vacuoles, and has succeeded 
ingenious experiments in producing vacuoles artificially. 
» OF some other suitable substance, which contained 
ufnahme und Ausgabe ungeléster Körper. Abhandl. d. Math.— 
- Bd. XVI., p. 149” (Bot. Centralbl., XLIV., 180.) 
haut und der Vacuolen, etc; Z. c. p. 185. (Bot. Ce 
