Prof. H. James-Clark on the Spongiz ciliate. 133 
XXI.—Notule Lichenologice. No. XX. 
By the Rev. W. A. Leicurton, B.A., F.L.S. 
Every lichenist is unfortunately well aware of the great diffi- 
culty of preserving specimens of lichens which grow on the 
earth. ‘I'oo frequently he finds, on consulting his herbarium, 
that the earth on which such lichens grew has become dry 
‘and crumbled into dust, involving in such disintegration the 
‘destruction of the lichen itself, especially when this happens 
to possess a crustaceous thallus. To remedy this a solution 
of gum arabic has been sometimes used, but with partially 
satisfactory results only, inasmuch as the mucilage does not 
penetrate the earth, but only conglomerates its surface. An 
effective preparation appears to have been discovered by 
M. J. M. Norman, of Trémso, Norway. It consists of a solu- 
tion of isinglass in spirits of wine, such as is used in the pre- 
paration of English adhesive plaster, which a chemist informs 
me is better known as “ Prout’s plaster.” This composition, 
when liquefied in a vessel plunged into water of the tempera- 
ture of 25°-30° C., is greedily imbibed by the earth on which 
the lichen grows, and becomes eilaeated. into a solid gelatine 
at a temperature below 15°. The solution may be applied by 
a camel’s-hair pencil until the earth becomes saturated ; but 
care should be taken that the lichen itself be not moistened 
with it, for otherwise it would become discoloured. When the 
surface has become dry, the specimen may be submitted to 
moderate pressure, which, after some days, produces the requi- 
site hardness and tenacity. The favourable experience of 
some years encourages M. Norman to recommend this prepa- 
ration to his fellow lichenists. 
XXII.—On the Spongie ciliate as Infusoria flagellata; or 
_ Observations on the Structure, Animality, and Relationship 
of Leucosolenia botryoides, Bowerbank*. By H. JAMEs- 
LARK, A.B., B.S., Professor of Natural History in the 
Agricultural College of Pennsylvaniaf. 
[Plates V., VI., VIL] 
I HAVE been engaged like others, for some time past, in en- 
deavouring to clear up the doubt which prevails in the scien- 
_ * A sketch of the contents of this memoir has already been published 
in the ‘ Proceedings of the Boston Society’ for June 20, 1866 ; the ‘Ame- 
rican Journal of Science’ for November 1866, and in the ‘ Annals’ for 
January 1867. 
+ From a separate impression from the ‘Memoirs read before the Bos- 
kegs of Natural History,’ vol. i. part 3; communicated by the 
author, , 
