ANDREWS: PROTOPLASMIC STREAMING IN Mucor 485 
A small capillary tube which had been filled with a 5 per cent 
solution of cane sugar was then carefully inserted under the 
cover glass and so placed that its open end was near one of the 
fungal filaments. In 10 minutes the sugar solution had diffused 
out in the water and come in contact with the filaments, and the 
protoplasm began to stream very fast to the point by the open end 
of the capillary tube. Sometimes the induced streaming was slow 
and then suddenly became more rapid. The capillary tube offered 
a convenient method of enabling one to bring the sugar solution 
to any desired part of a filament and thus study the behavior at 
certain places. No perceptible difference could be detected in 
this way between the base and apex of filaments capable of active 
streaming. At whatever part of an active filament the capillary 
tube containing the 5 per cent solution of cane sugar was applied 
streaming to that point was always induced and in a very short 
time. As was to be expected, weaker solutions of the cane sugar 
required more time and produced slower streaming while more 
Concentrated ones caused more rapid streaming in less time. This 
method of using the glass capillary tube is not quite so simple as 
it may seem, as certain mechanical difficulties are experienced, 
especially when it was used with objectives of sufficient power to 
see the streaming distinctly. 
A somewhat similar experiment in principle is one in which 
streaming almost immediately began in the filaments when a drop 
of sugar solution was brought to the edge of the cover glass. Here, 
however, the movement stopped sooner than when the solution 
Was applied at one place by means of a capillary tube, since it 
diffused all around the filaments and the water was more quickly 
and uniformly withdrawn. 
I can confirm the experiment of Schréter* in which he found 
that a sugar solution added to one side of the cover glass caused 
Streaming in that direction, and I found that it continued from 
? to 1714 minutes according to concentration and the condition 
of the filaments. This is the time for both Mucor Mucedo and 
M. Stolonifer. Also, I have found that the excessive loss of water 
bya Sugar solution results in a great decrease in the size of the 
* “4 . 
Schréter, loc. cit. 21, 22. 
