NOTES AND MEMOEANDA. 
289 
An amorphous Bed Alga (undescribed) parasitic in Halichondria 
plumosa. 
Oscillatoria. 
Scijtonema. 
Palmella spongiarim. 
Saprolegnie^. 
Spongiophaga communis. A minute, sLort, nematoid filament, with 
a bulb at each end, which multiplying to an enormous extent, especially 
in the Hircinioe, may become a pssudomorph of the sponge it attacks, 
so as to be mistaken for the sponge itself. 
Saprolegnious Mycelium. 
Under “ Foreign Objects,” Mr. Carter refers to a little prism of 
calcite banded occasionally with yellow, brown, red, or amethystine 
colours, separately or more or less united in the same prism, which so 
frequently occurs in the Psammonemata derived from the disintegration 
of thin shreds like Crenatida phasianoptera, which are made up of 
similar prisms. 
Under Dendrites, he refers to the little colourless circular 
dendritic spots which appear on old kerataceous fibre, and whose 
structure is so minute, that under a inch with high ocular it does not 
appear satisfactorily. All that can at present be stated of them is that 
they are composed of branched filaments which radiate from a central 
point, but whether they are algoid or fungoid, or what their real nature 
is, future observation must determine. 
A Neiv Double Staining. — Dr. P. Schiefferdecker, of Eostock, 
describes in the ‘ Archiv f. Mik. Anat.,’ vol. xv. p. 30, a process which 
he has used since 187 6. He says : — “ From my own experience, which 
has embraced almost all the tissues of animal structures, I can most 
warmly recommend it. I use the eosin, which Fischer introduced 
some time ago, and dahlia, methyl-violet, and anilin green. These 
have a very similar action, though sometimes they show definite 
specific differences. 
The chief advantage of the new method is that in the compound 
organs the individual elements of the tissues or even different sections 
of the same tissue are very sharply distinguished by differences in 
colour which readily strike the eye, so that preparations for demon- 
stration may be produced with really surprising beauty. The different 
colours harmonize with each other, the method is easily and quickly 
apjdied, and the tissue may be hardened directly in the alcoholic 
eosin solution. The durability of the preparations is also satisfactory, 
although under certain restrictions. They will only bear to be mounted 
in varnish, and must be kept in the dark, as the light affects the eosin. 
The method can be applied both to preparations which have been 
hardened in alcohol or in chromic acid, or even its salts. The tint 
of the colours is, however, often different in the two cases. 
The procedure is as follows : — The eosin is used according to 
the directions of Fischer,* in an alcoholic solution, and 1 per cent, 
solutions in water are made of dahlia, methyl-violet, and aniline 
* ‘ Archiv f. Mikrosk. Anat.,’ vol. xii. p. 349. 
