1899] SPORE-MOTHER-CELL OF ANTHOCEROS 105 
units before the second mitosis which is more rapid than the first. 
There is finally a period of 3-6 units before the spores are 
definitely organized by the partition walls across the spore- 
mother-cell. 
The results presented by this investigation indicate that the 
Hepatice are likely to furnish some very interesting material 
for future researches in cytology. From superficial examination 
it appears probable that the Ricciacee and Marchantiacee in 
general present mitoses similar to Anthoceros, but we may hope 
that some forms exist that will harmonize the peculiarities 
described for the Jungermanniacez with the conditions found in 
Anthoceros. 
EXPERIMENTAL TECHNIQUE. 
As stated in the beginning of the paper the writer experi- 
mented with a number of fixing agents to determine as precisely 
%s possible their merits or faults. Of these Flemming’s formula 
“esignated “weak ” gave decidedly better results than any other. 
Anthoceros, and presumably for other types, the chief test of 
a fixing fluid is its effect upon the achromatic parts of a nuclear 
figure. Chromosomes are the least difficult of all the nuclear 
— to preserve. Preparations will not infrequently present 
a — of nuclear plates when the spindles are manifestly 
wee dition. The following is a brief statement of the 
cell. Several fluids upon nuclear figures in the spore-mother- 
oo acid fixes filarplasm but the safranin stains dif- 
Spindle a soa gentian violet does not hold well in the 
days in ie i sections fastened to the slide be left several 
Sentian violet lemming the staining qualities with safranin and 
are much improved although, it is doubtful if 
they ¢ 
a made as good as those presented by Flemming fixed 
Merkel’s fluid 
Platinum chlorid 
Petiods (36 hou 
badly fixed 
(1 per cent. chromic acid 12°, I per cent. 
2°, water 72°) even when used for long 
ts) is thoroughly unsatisfactory. The spindles 
