ANDREWS: PROTOPLASMIC STREAMING IN Mucor 483 
slowly at first; then placed over the 20 per cent glycerin alone 
its streaming continued slowly for 15 minutes to the tip. When 
this specimen was again placed over pure water streaming began 
very rapidly from the tip and continued so for to minutes, but 
again it moved to the tip when the air was slightly dried. The 
4 per cent solution of ethyl ether used in this experiment was 
still further weakened to 1% per cent when it was added to the 20 
per cent glycerin. The same experiment was carried out over a 
full 14 per cent ether. As above mentioned a temporary awaken- 
ing of the protoplasmic activity occurred. Schréter* states that 
a 4 per cent solution of ether in a glycerin solution will stop 
streaming, but he does not state the concentration of the glycerin 
or the time required. This I also found to be true as above stated, 
but he has evidently overlooked the fact that a very weak solution 
of ethyl ether in dilute glycerin may cause a temporary recom- 
mencement of streaming if the ether is immediately applied. 
In either case it shows that transpiration is not purely mechanical 
but that certain physiological factors enter into the process. The 
above experiment is not easy to perform, owing to the liability 
of the protoplasm to lose too much water before the ether may be 
Properly caused to act upon it. A reawakening of protoplasmic 
activity resulting in earlier or increased growth has been shown 
for other plants by Johannsen.t While this is true of small 
amounts of ether, by increasing the dose to a certain concentration 
not only a mere awakening of activity was caused but a more 
rapid growth.t In these experiments with a weak solution of 
ether on the fungal filaments a great many groups of the fungi 
Were grown on a glass plate which fitted a large glass cell tightly. 
An apparatus like FIG. 5 is convenient to use to quickly draw into 
a cell a solution of glycerin and ether. By opening the stop- 
Cock A and applying suction at C the 20 per cent glycerin is 
drawn out, and then by turning the three-way stopcock A again 
and opening B the desired glycerin and ether mixture in D is 
drawn into E under the specimens at F. 
Strong solutions of ether in glycerin caused an unfavorable 
* Schréter, loc, cit. 20. 
+ Johannsen, W. Das Aether—Verfahren beim Friihtreiben 61. . 1906. 
t Johannsen, loc. cit. 61. 
