288 Lister.— On Chondrioderma differ me 
The spores of Ceratium hydnoides , gathered more than 
a year ago, still give birth to their remarkable swarm-cells 
abundantly, in about twelve hours after being placed in pure 
rain-water \ 
With many other species I have had similar results, 
germination taking place in from six hours to several days, 
but with some I have failed altogether. My experience with 
Stemonitis fuscci leads me to suppose that in these last I may 
only have been unsuccessful in obtaining favourable specimens. 
Nearly all my experiments have been made with filtered rain- 
water. 
The conditions under which the spores are placed have 
a marked influence on the development of swarm-cells. Thus 
the spores of the specimen of Stemonitis fusca above men- 
tioned, where germination takes place rapidly, will remain at 
the bottom of a test-tube half filled with water for many days, 
if not permanently, without germinating, while if some of these 
spores are taken out of the test-tube where they have lain 
for some days, and placed by means of a pipette under 
a cover-slip on a glass slide, the swarm-cells appear in the 
course of an hour or two. This has been the case with 
several other species which I have treated in the same manner, 
though it is by no means a constant rule. 
Arcyria punicea , Perichaena corticalis , Badhamia panicea 
and some others have germinated almost equally rapidly 
under a cover-slip, in a hanging drop, or at the bottom of 
a test-tube. 
In the numerous gatherings and cultivations of Chrondrio- 
derma difforme which I have examined, the spores have been 
very constant in the time they take to hatch. Under a 
cover-slip or in a hanging drop the swarm-cells begin to 
emerge in six to eight hours. Although deep immersion 
delays, yet it does not prevent their germination. 
The following experiments relating to the formation of 
plasmodium under a cover-slip and in a hanging drop fur- 
1 De Bary mentions (loc. cit., p. 448) that the spores of Ceratium do not ger- 
minate in pure water, but only in a suitable nutrient solution,. 
