82 Wisconsin Academy of Sciences, Arts and Letters. 
carp will throw light on the question as to the presence in the 
sporocarp cells of the blepharoplast, or of structures related to 
it and finally giving rise to it. It was with these problems 
especially in view that I undertook the investigations here 
described. 
The material was obtained from plants of M. quadrifolia 
growing in the greenhouses connected with the botanical labora¬ 
tories of the University. Flemming’s stronger and Flem¬ 
ming’s weaker chrom-osmium-acetic fixing fluids, as well as 
some modifications of the same, were used for the most part 
and gave the best results. In general, the original formulae 
as published by Flemming gave at least as good if not better 
results than the various modifications of the same which have 
from time to time been recommended. Several sublimate mix¬ 
tures were also used but did , not give results equal to 
those of the chrom-osium-acetic mixtures, although they 
gave valuable control preparations. For staining, 
Flemming’s triple stain and Heidenhain’s iron-haematoxy- 
lin were used almost exclusively. The sporocarps of Marsilia 
oifer a most favorable material for cytological study. They 
are readily obtained in all stages of development, fix well, and, 
contrary to what might be expected, section easily. The dif¬ 
ferent parts of the cell take a good differential stain with the 
triple stain, so that preparations of unusual brilliancy result. 
Furthermore, the cells found in the sporocarp offer an in¬ 
teresting variety. There are the ordinary vegetative or somatic 
cells of the sporocarp Avails, etc., which may be looked upon as 
typical vegetative cells. In young sporocarps these are actively 
dividing, so that abundant instances of the various stages of 
spindle formation are to be found. The tapetal cells represent 
another type of somatic cells, i. e. cells which are soon to dis¬ 
integrate. For such cells, aberrant nuclear and cell divisions 
have been described for a large number of plants and animals. 
Then there are the “germ cells,” the spore mother-cells and 
their ancestors. In the spore mother-cells we have cells which 
have severed their structural connection with other cells, so that 
they do not form an architectural part of a tissue, at least not 
in the later stages of their development when they are begin- 
