ANDREWS: PROTOPLASMIC STREAMING IN MuCoR 491 
an exact per cent is not required is to place on the under side of 
the cover glass a small grain of sugar, close to the water in which 
the spores of the fungi have produced filaments. The sugar will 
adhere to the moist surface of the glass. A thick ring of vaselin 
may be put on the edge of the glass ring cell, which prevents the 
cover glass from coming directly in contact with the glass cell and 
admits of a fine platinum wire being introduced between them 
without admitting air. When the streaming has ceased for any 
reason or become retarded, the particles of sugar may be shoved 
into the liquid containing the fungal filaments by means of the 
Platinum wire and its effect observed immediately through the 
microscope. We have in this arrangement not such a change as 
might bring about streaming by the drier air of the room entering 
the glass cell when the filaments are growing. Streaming would, 
as shown before, occur by transpiration, if in the experiment here 
mentioned the filaments protruded beyond the edge of the drop. 
In such a case it would be difficult to determine how much of the 
accelerated or induced streaming is due to transpiration and how 
much to osmosis. In the method here outlined, however, the 
factor of transpiration is excluded and osmosis alone is responsible 
for the result. All the experiments tried in this way resulted, as 
*xpected, in streaming being induced or accelerated, and they thus 
‘onfirmed the previous and similar ones of this paper. In like 
Manner the result was confirmatory of and useful in the experi- 
ments just performed with ether. Where the streaming had been 
Stopped by the addition of ether in any of the stronger solutions 
mentioned, it could always be awakened and caused to continue 
rom 1 to 15 minutes, according to the strength of the ether, its 
time of action, and the quantity of sugar. The sugar was placed 
on the cover glass at the same time the ether was added to the 
Specimen, 
INJURY 
Frequently injuries of various kinds, if not too severe, cause 
Protoplasmic streaming in many plants.* Generally a rather 
Serious injury is necessary to stop the protoplasmic movements 
Amanently. Ternetzt found in Ascophanus carneus that by 
* Pfeffer, W. Plant Physiology 2: 816-820 and literature there quoted. 1905. 
t Ternetz, loc. cit. 282. 
