147 
out a lashing flagellum. An interesting article was published by 
Dr. Jahn in 1904, in which he shows that in some species of 
Mycetozoa the flagellum is produced before the separation of 
the daughter swarm-cells, and is seen to be a continuation of the 
achromatic fibres of the nuclear spindle; he considers the darkly 
staming point at the base of the flagellum is the centrosome. 
We have had the privilege of seeing his beautiful preparations. 
It is uncertain how often the swarm-cells divide ; the division 
can be followed for three or four times, and probably the number 
varies according to circumstances, but eventually the tendency to 
divide ceases, the flagellum is withdrawn, and the swarm-cells 
creep about in amoeboid form. At this stage, when they meet in 
their wanderings they fuse together, though their nuclei remain 
distinct, and when a number have thus coalesced they appear to 
act as centres of attraction towards which others converge until 
the plasmodium with its rhythmic streaming of circulation is 
produced. The rapid flow, as we see it under the microscope is 
always an impressive object, the more so perhaps because it is 
so difficult to explain. In the creeping swarm-cell, the changing 
currents in the granular. protoplasm are very similar to what we 
observe in an amoeba, and the streaming of the plasmodium is a 
further development of that movement on a large scale. Under 
normal conditions the flow proceeds through the net-work of 
channels for a minute and a half, when it stops and immediately 
reverses its course, maintaining a rhythmic change backwards 
and forwards at nearly equal intervals of time but always rather 
longer in the direction in which the mass is advancing. 
The plasmodium condition is the main stage in the life of the 
organism ; the dividing of the swarm-cells at the beginning of 
the cycle and the formation of spores at its close occupy a very 
short time as compared with the prolonged existence of the 
plasmodium, which may last for weeks or months or perhaps 
years, 
The plasmodium of nearly all the Mycetozoa appears to feed 
on decayed vegetable matter, either dead leaves or rotten wood. 
he species only, to my knowledge, devours living fungi; this is 
adhamia utricularis + it preys principally on different species 
of Stereum and is abundant in our Forest when Stereusm hirsutum 
s plentiful. This circumstance is favourable for its cultivation. 
' readily passes into the sclerotium or resting stage when de- 
Prived of moisture, in which state it can be preserved for several 
years without losing its vitality. 
The Photograph on the wall represents the plasmodium of 
this species which had been induced to creep over a thin cover- 
Sip; it was killed with absolute alcohol, stained with magenta, 
and mounted in Canada balsam. The dark turgid edge along 
the top shows where it was advancing, forced forward by the 







