292 Lister . — On Chondrioderma differ me 
the swarm-cells make their appearance in great abundance. 
The plasmodium is very inconspicuous. I have had dead 
leaves kept wet under a bell-jar, among which it must have 
crawled for many days, but, though carefully watched, the 
first indication of its presence was the appearance of a pale 
young sporangium, which developed into the normal form. 
The only species, besides Chondrioderma difforme , with 
which I have obtained plasmodium in a hanging drop is 
Stemonitis fnsca. Swarm-cells appeared the day after sowing 
the spores, and in twelve days a small plasmodium was seen ; 
this increased to considerable dimensions, principally, as it 
appeared, by the absorption of microcysts, as described p. 9, 
but at the end of a fortnight it changed into macrocysts without 
further development. This plasmodium exhibited several 
curious peculiarities as compared with that of species found on 
dead leaves, etc., which may perhaps be owing to its natural 
habitat being the substance of rotten wood. 
At a meeting of the Linnean Society, in April, 1889, I 
described the mode of feeding which I had observed in the 
swarm-cells of Stemonitis fnsca. I have since been able to 
watch the same process in the swarm-cells of several other 
species. Those of Perichaena corticalis afforded an interesting 
instance, because of the great activity of the bacilli which 
abounded in the preparation, and as showing the voracity of a 
few individual swarm-cells. One was noticed which already 
contained four vacuoles stuffed with bacilli, probably six to 
eight in each. It was observed to throw out several long 
pseudopodia from the posterior region, to which active bacilli 
became attached. In the course of twelve minutes four were 
seen under a Beck’s T V h immersion lens to be drawn in and 
conveyed into freshly formed vacuoles. 
I have repeatedly seen bacteria taken by swarm-cells of 
Chondrioderma difforme in the manner above described, and 
it would appear that bacteria form their principal food 1 . On 
one occasion I had a favourable opportunity for observing the 
1 The vacuoles in the plasmodium of Chondrioderma difforme are frequently 
seen to contain bacteria, 
