86 BOTANICAL GAZETTE [Aucusr 
that they are caused by a pull upon the nuclear membrane (fig. 3). 
Besides, the membrane in sections can be seen to be wavy, showing 
that it is not under tension from a dynamic center. The lobing 
occurs long before fibrillar elements are visible, and if the assumption 
that fibers are the expression of lines of force be true, then such lines 
of force do not exist at this time, and hence the irregularities in the 
shape of the nucleus cannot be attributed to a pull by them. It 
would seem much more probable that they are due to an amoeboid 
_ movement of the nucleus. It is well known that the nucleus of — 
certain cells possesses this power, and observers have noted the 
phenomenon in living cells. It has also been noted that there is — 
in a Measure a correspondence between the shape of the nucleus — 
and that of the cell to which it belongs. When the cell is much — 
attenuated the nucleus is greatly elongated. In jig. 28 is shown 
a resting nucleus from an elater of Pallavicinia. Miss MERRIMAN 
(14) discusses this question in relation to the differentiation of tissues _ 
from the meristem in the root tips of Allium and attributes to the 
nucleus the power of amoeboid motion. KorscHELT (12) describes — 
in the egg of the water beetle Dytiscus a nucleus with pseudopodia~ 
like processes extending out into a mass of granular food particles: 
As previously stated, the resting nucleus of the already deeply 
lobed spore mother cell is spherical. In preparation for division — 
the great changes which take place in its size and in the charactet 
of its contents must be connected with great metabolic changes 
going on within it. The materials necessary for the supply of tis — 
demand must come from the cytoplasm, which in this case consists 
Of four masses occupying the four lobes of the spore mother cell, 
and the reaching out of the nucleus for food might tend to produce 
a tetrahedral form. Bes 
