144 
ALBERT H. TUTTLE 
karyokinesis in this genus. By the use of an original and valuable 
(but exceedingly difficult) technique this investigator was enabled 
to make important additions to and corrections of the results of 
his predecessors : among the most noteworthy of these is the de- 
termination of the number (19) of chromosomes in the species 
studied by him. 
The present paper is an attempt to give an independent account 
of the process as observed by me; presenting some facts that the 
writers mentioned have not recorded or figured, and calling special 
attention to some noteworthy features which are indicated in 
the drawings hitherto published, but of which only casual men- 
tion, if any, has been made. 
A species of (Edogonium established itself a few years ago in 
the basin of a public drinking fountain in one of the streets of 
Charlottesville. When found it was growing abundantly, along 
with other freshwater algae; collections were made at frequent 
intervals for over a year; but although the current through the 
basin was but slow, it was sufficient to prevent fruiting; and efforts 
to cause the plant to fruit in still water in the laboratory were 
unsuccessful. I am, therefore, unable to name the species with 
certainty. Material from this source was collected and put (while 
at the fountain) in various fixing solutions: chromacetic (of 
different strengths), acetosublimate, and chromosmacetic solu- 
tions : were used, but by far the larger portion of the material was 
fixed with chromacetoformol. While this solution causes some 
shrinkage of the cytoplasm from the cell wall, it is in other respects 
an admirable fixing agent, and its results have been carefully 
checked with those of others. While various stains were used 
reliance was chiefly placed upon iron-hsematoxylin, with or with- 
out a secondary stain. 
Frequent attempts were made to study the living cells, but with 
no satisfactory results. As Van Wisselingh has already pointed 
out, the extent and density of the chloroplast and the abundance 
of large pyrenoids render this mode of study well nigh hopeless. 
While some study was made of celloidin sections, all of the draw- 
ings were made from material stained with iron-hsematoxylin 
and mounted in dammar. 
