26 Wisconsin Academy of Sciences, Arts, and Letters v 
small. The chromosomes are relatively large and form a very 
compact group. The spindle is as in the other tissues broad- 
poled. Slightly over a third of the chromosomes are repre¬ 
sented in the drawing. 
As a result of this division, sixteen spore mother cells are 
formed. The cells were carefully counted. Camera lucida 
sketches were made of successive sections of a sporange and 
these sketches were carefully studied and compared and the 
number of cells thus determined. The result was invariably 
sixteen. 
These sixteen young spore-mother cells are normal in ap¬ 
pearance. (Figure 43.) As a rule they are angular and 
nearly isodiametric, but a few are more elongated. The cell 
wall, if present, is very thin. The cytoplasm is dense and is 
free from darkly staining granules. The nucleus is rounded 
and is ordinarily at the center of the cell. The chromatin 
forms a loose reticulum consisting of small aggregations con¬ 
nected by delicate strands. The amount of nucleolar material 
varies greatly. In some nuclei there are three or four good- 
sized nucleoles. 
In the next stage we find that the sixteen spore mother cells 
are fusing in pairs. The fusion figures are numerous and 
unmistakable, and as the cells are large and easily fixed and 
stained, the process can be followed in detail. The drawings 
of these fusion stages are all made on the same scale. They 
are magnified nineteen hundred and fifty diameters. 
A stage showing the earliest indications of fusion is repre¬ 
sented in figure forty-four. In this instance, the nuclei are no¬ 
where in actual contact, but the cells are united along one side. 
The chromatin is in the form of fine, uniform, much convoluted 
threads. There are several nucleoles in each nucleus. On 
each nucleus there is a slender pointed projection extending to 
the plasma membrane. Each of these projections contains a 
loop of the spirem. The projection on the one nucleus is ex¬ 
actly opposite the one on the other but the plasma membranes 
of the two cells are not quite in contact at this place. The sur¬ 
faces of the nuclei are smooth and rounded except at the points 
where these beaks protrude. 
