284 Lister . — -On Chondrioderma diff or me 
increased in number in the same manner as in the other 
experiment ; but these differed from the first in having the 
plasmodium almost entirely colourless and the bases of the 
sporangia only faintly tinged with yellow. 
A subsequent cultivation was made with cress-seeds and 
the spores from a sporangium with strikingly dark capillitium 
(Fig. 4 a). In the course of 11 weeks 310 sporangia were 
produced on the blotting-paper and cress-stalks ; the capilli- 
tium in these varied in tint from that of the parent to 
colourless, and in amount from abundance to scarcity. 
(Fig. 4 b and c .) 1 
In order to ascertain whether the time of the development 
of sporangia depended on the condition of the young cress- 
plants, three pieces of wet blotting-paper were sown with 
cress-seeds on the same day, and covered with bell-jars. The 
spores of three sporangia from the cultivation producing 
310 fruits w r ere sown ; those from one at the same time 
as the cress ; from another four days after, when the seeds 
had sprouted; and from the third eight days after the cress 
was sown. In the first, a sporangium appeared on the 
thirteenth day, on the following day there were three ; the 
numbers increasing day by day to 5, 20, 24,40, 80,125. Under 
the second bell-jar, three sporangia appeared twelve days 
after the spores were sown or sixteen days after the cress. 
The daily increase in numbers was as follows, 5, 10, 20, 40, 50. 
Under the third, four sporangia were seen on the tenth day 
from sowing the spores, but the blotting-paper was allowed 
to become too wet, which checked further increase. 
1 In subsequent examinations of many sporangia from this large cultivation, the 
spores were usually found to be of the normal size and dark purple brown in colour, 
but in a few they were pale violet, and varied much in form and dimensions. I 
had little doubt that these were imperfectly developed, and that I should find, as 
I have often done in other species when the spores have not properly matured, that 
germination would not take place. To test the point a large number were placed 
in water under a cover-slip ; next morning almost all had hatched, large and small, 
regular in form and irregular, the swarm-cells were as vigorous as those from the 
dark spores, and in a few days many had coalesced into young plasmodia. 
I have frequently met with considerable difference of colour in the spores of some 
species f Didymium and Stemcnilis, but not to the extent exhibited in this case.- 
