Badhamia utricularis and Brefeldia maxima . 19 
When the process is going on slowly we may sometimes 
notice all these stages in one lobe of plasmodium ; at one 
extremity there may be a thin film showing streaming move- 
ment with no aggregations ; then follows the mottled ap- 
pearance, and further on the definite thin-walled cells may 
be traced, densely crowded and constituting the thick 
sclerotium. Sometimes a piece of plasmodium will become 
detached on the glass plate, and be left behind by a retreating 
wave, and will form into cells while all the rest continues its 
streaming movement. 
I have had plasmodium change to the sclerotium form 011 
wet cotton wool, but this was probably from want of nourish- 
ment. As the supply of moisture was here abundant, the 
margin of the sclerotium was not so abrupt as usual, and in a 
narrow border the cells were spread in a thin layer ; many of 
the outermost were quite detached from the rest, and showed 
slow amoeboid movement. 
The chief cause of the resting condition in Mycetozoa, as is 
well known, is lack of moisture. 
When I changed my place of residence last spring, and 
wished to take with me the store of plasmodium which 
was in active state under a number of covers and in 
glass boxes, I removed the glass shades from those not 
required to be retained in the streaming condition. They 
at once began to form into sclerotia, and in three days 
were dry and ready to be packed away. After the lapse 
of five months, on adding water to parts of these sclerotia, 
the thin hyaline walls of the cells broke down and were 
dissolved, and in three or four hours the streaming move- 
ment returned. 
On October 16, I had a rich plasmodium covering a pile of 
Stereum under a large bell-jar, which was inadvertently exposed 
for about three hours to hot sunshine. At the end of that 
time the whole of it had changed to fine rugged sclerotium, 
which I removed from the bell-jar and set aside. When 
portions of this were wetted again within a few days they 
returned to the active state in about half an hour; when 
C 2 . 
