1901) MICROSCOPICAL JOURNAL. 189 
dium chloride, Rabl’s fluid, bichromate-osmic, and osmic 
vapor. . 
‘Hermann’s fluid gave the best results, though subli- 
mate-acetic, absolute-acetic, Boveri’s picro-acetic, Flem- 
ming’s and Vom Rath’s solutions proved quite satisfac- 
tory, and osmic vapor was especially valuable for tempo- 
rary im toto preparations in the study of division stages. 
Peptone and pepsin solutions, bichromate of potash 
(one to three per cent), formalin (one-tenth to one per 
cent)and fresh water were employed as macerating agents; 
of these, potassium bichromate (two per cent) was found 
to be of greatest value in revealing and isolating in inter- 
‘nal fibre structures of Licnophora. 
The principal stains used were Delafield’s hamatoxy- 
lin, dahlia, bismark brown, thionin, methylen blue, acid 
fuchsin, borax carmine, alum carmine, picro-carmine, 
Mayer’s paracarmine, light green, safranin, Heidenhain’s 
iron-heamatoxylin, rubin, and ruthenium red. For fresh 
material picro-carmine and alum carmine gave the best 
results; borax carmine, paracarmine, light green, and 
safranin were useful in the study of fixed material in toto; 
for sections no other stain was at all comparable to Heid- 
enhain’s iron-hematoxylin following Hermann’s fixing 
fluid, and used either alone or in combination with rubin 
or with ruthenium red. 
Structure and General Biology.—Licnophora like most 
of the Ciliata has a delicate structureless pellicula not dis- 
tinguishable in life, but readily separated from the cyto- 
plasm by macerating fluids and by many fixing agents. 
The ectoplasm is clearly marked only at the margin of 
the attachment disc, between its cuticula and fibre layers, 
and within the triangular basal portion of the oral band 
where it is either homogeneous or very finely granulr. 
The entoplasm is coarsely alveolar in both discs and more 
finely alveolar in the neck. 
Oral Disc.—The oral disc is irregularly circular in out- 
