Farmer. — On Isoetes lacustris , L. 
55 
is separated from the cytoplasm by a well-marked membrane, 
is of a very watery consistency, and is so poor in chromatin as 
to be scarcely stained at all by reagents more especially used 
for nuclear structure, as methyl-green, safranin, or haematoxy- 
lin, although the nucleoli are rapidly and intensely coloured ; 
and it is to these facts that the great difficulty of following out 
the changes which take place in the nucleus during the earlier 
stages of germination is to be attributed. 
In the mature spore the apical portion (in which the nucleus 
is imbedded) is clearly separable from the remaining larger 
part by the dense character of its protoplasm, and the com- 
parative absence from it of the reserve stores of starch and 
oil ; and this differentiation becomes more and more obvious 
as the formation of cell-walls approaches. I have not, in spite 
of careful search through many hundreds of spores, succeeded 
in recognising the nucleus at this stage ; probably the nucleoli, 
during its division, may suffer disintegration, and diffusion into 
the cytoplasm as the result of the heat necessarily employed 
in parafin-embedding. 
But although the changes in the nucleus remain obscure, 
the other processes attending germination are clear enough. 
The mass of protoplasm already mentioned as occupying the 
apex of the spore becomes traversed by fine cracks coinciding 
in their general directions with the positions ultimately taken 
up by the young cell-walls. I have no doubt that this splitting 
is subsequent to, and perhaps conditioned by, the division of 
the spore-nucleus, though direct evidence is wanting on this 
point. After cell-formation has begun, it proceeds with great 
rapidity, though in a manner differing in the two regions of 
the spore already alluded to. Figure 17 exhibits one of the 
earlier stages, and is intelligible when it is borne in mind that 
the section has passed obliquely below the spore-apex. Figure 
1 8 shows clearly the differences in the process of division pre- 
vailing in the upper and lower part of the spore, the extreme 
slowness with which the process is conducted in the lower part 
being strongly contrasted with the rapid cell-increase in the 
upper portion. The divisions in the latter region lead to the 
