Igor | CURRENT LITERATURE 147 
By use of high magnification the protoplasmic strands in Allium root 
tips can be shown to be bundles of fibrillae. These fibrillae have a definite 
sheath and lie embedded in a special plasma. In other plants the fibrillae 
could not be so well made out, but enough was accomplished to convince the 
author that, in general, the longitudinal strands are fascicles of smaller 
author supposes that the fibrillae are in contact, or perhaps continuous, 
through these walls. Transverse fibrils were found in certain cells, but never 
in bundles. 
The question whether or not these fibrillae have any connection with the 
transmission of traumatropic and other stimuli is a difficult one to answer. 
The influence of a number of changes in external conditions was determined, 
first with regard to the propagation of the traumatropic reaction, and then with 
regard to the fibrils. It was found that the conditions which cause a degen- 
eration of the fibrillae diminish the rate of propagation or cause this phenome- 
non to cease altogether. By a sudden change in temperature the fibrils may 
of this power to the cells is always accompanied by the regeneration of the 
fibrillae. 
Another line of evidence is furnished by the study of certain roots of 
Allium which exhibited an apparently spontaneous nutation, uninfluenced by 
gravity. In these the starch-bearing cells of the root cap were perfectly 
normal in appearance and behavior, but in almost all of these roots the 
bundles of fibrillae were disorganized. Still other evidence btained from 
Vicia faba. In roots of this plant the fibrillae are found only in the large 
plerome cells. If the plerome is severed bya knife-thrust the geotropic reac- 
tion either occurs not at all, or bending takes place only so far up the root as 
the wound. Némec concludes that the bundles of fibrils are the path of con- 
duction for traumatropic, geotropic, and other stimuli. The fibrils are strands 
of protoplasm specialized for conduction. 
The two pieces of research here reviewed are accompanied by figures 
which are certainly convincing with regard to the facts. To us it appears that 
the conclusions of the second paper are much better supported by experi- 
ment than those of the first. The bundles surely bear a close relation to the 
process of conduction, whether this relation be causal or not. The author 
compares the fibrils to the nerve fibers of animals, but it seems to us that 
there is little similarity--BurTON EDWARD LIVINGSTON. 
