1890.] Botany. 677 
methods used for obtaining good sections from them must vary greatly. 
I have prepared and sectioned fungi, lichens, the cotyledons, plumules, 
hypocotyledonary stems, roots, and root-tips of the cucumber, young 
pine cones, young wheat blades, lilac buds, and bean stems, with vary- 
ing degrees of success. 
Lichens, and the young firm cotyledons of the cucumber could be 
dehydrated, and permeated with paraffine much more rapidly than 
young meristemic tissue, or tissue composed largely of cellulose and 
water. The former may be placed in 50 per cent., 75 per cent., 9o per 
cent., and roo per cent. alcohol, chloroform, chloroform and paraffine, 
and finally in paraffine, at a temperature of 55? C., remaining in each 
from two to twelve hours, and good results may be obtaise 
But the meristemic and the thin-walled watery tissue must be 
treated differently, or the tissue will come through very much shrunken 
and distorted—worthless biologically. 
I have had the most success following the method described by Dr. 
J. W. Moll, in the Botanical Gazette for January, 1888. I have 
obtained good sections from all the material that I have treated in this 
way. I used a ı per cent. solution of chromic acid and 20 per cent., 
35 per cent., 5o per cent., 75 per cent., and go per cent. alcohols for 
dehydrating. The chromic acid seems to fix the protoplasm, and 
macerate the cellulose, allowing the alcohols to pass more freely. I 
allowed the specimens to remain in the several per cents. of alcohol 
from two to twenty-four hours, according to their size and texture. As 
as rule, I found that the more gradually the specimens were dehydrated 
the better. From absolute alcohol, the specimens were placed in a 
solution of equal parts of turpentine and paraffine. The solution con- 
taining the specimens was then raised gradually from a temperature of 
20°+ C. to about 45? C. They were then placed in melted paraf- 
fine, kept as nearly at 50° C. as possible. Small specimens will be 
permeated in one or two hours, but large specimens require from four 
to six hours. 
From the 75 per cent. alcohol I placed the specimens in a stain. 
The stains I tried were alum cochineal, hzematoxylin, fuchsin, methyl 
green, methyl blue, methyl violet, and ammonia carmine. I found 
alum cochineal a good stain for fungi, plumules, stems, roots, and root- 
tips, but it would not penetrate the cucumber cotyledons, Fuchsin 
would penetrate anything I tried ; but as it is soluble in alcohol it is 
necessary to over-stain the specimens, and then allow the coloring to 
come out until it is about right. Haematoxylin stained all the tissue 
that I tried except the young cucumber cotyledons. This stain gives 
