42 MINNESOTA BOTANICAL STUDIES. 
inner cells of the conceptacle, the paraphyses, odgonia and 
antheridial hairs stain light red, the deeper cells of the con- 
ceptacle purplish, the pith cell walls dark red, while the color 
is all washed out of the matrix. Differentiation is also pro- 
duced between different cortical layers, epidermis and cuticle 
and pith. 
Methyl] blue alone is a fairly good wall stain, but must be 
washed with care or it will all wash out. It also stains the 
chromatophores deeply. In this way the nuclei in the not too 
opaque odgonia may be located, they shining through as lighter 
areas in the dark mass of the odgone. Methyl violet is a 
quick stain. Over-stain and wash out as desired. 
Bismarck brown was a very satisfactory stain for mapping out 
cell structure distinctly. It stains the inner wall of the cells 
(dark) brown, and the pith yellow. Itis also useful in studying 
the structure of the conceptacle, the gelatinous sheath around 
the odgone being nicely brought out. It is a quick stain. 
It may either be used dilute and allowed to stain longer, or 
more concentrated and then washed out till desired effect is ob- 
tained. Either way is good. 
Hematoxylin dyes are better than carmine for nuclei. The 
most satisfactory results were obtained by bleaching the sections 
in chlorine gas for ten to fifteen minutes, then staining from one 
to two days in hematoxylin, then washing out till the walls and 
matrix were nearly clear, while the nuclei retained the stain 
longer. The chromatophores stain in hematoxylin and thorough 
washing is necessary to make the nuclei appear. Delafield’s 
hematoxylin was found a good kind. ‘The best effect was 
obtained by using a hematoxylin (brand unknown) that had 
been kept in solution at least ten years. 
Iodine is very satisfactory for staining the protoplasm, and is 
very helpful in studying the pits between the cells, and in 
studying the contents of the conceptacular organs. 
The staining was done on the slide. Rather concentrated 
dyes were employed. For alcoholic solutions of dyes 70 per 
cent. alcohol was used. 
