0) CELL AND NUCLEAR DIVISION IN FULIGO VARIANS 243 
plants. He also specifically states that typical mechanomor- 
phoses are the cell nets in growing points of young organs and 
structures whose cells show no individual growth after cell division is 
complete. All the sporanges mentioned above would be included 
in this latter type of structures. The sporange of Synchitrium 
isaspherical mass of protoplasm which divides into cells which 
show no further growth, at least till after cleavage is complete. 
At this stage, then, the cleavage planes shouldiillustrate typical 
mechanomorphosis. It would seem that in such a spherical 
mass of undifferentiated protoplasm the opportunity for the law 
of rectangular intersection to come to full expression would be 
especially good. We might expect the periclinal and anticlinal 
Cleavage planes to be extremely conspicuous in suchacase. On 
the contrary, as noted above, and as is well shown in figs. 2, 
#14, 15, pl. 24, of my former paper (4), no regular periclines 
and anticlines are to be observed. The surface furrows cut into 
the mass at very varying angles, frequently also becoming 
curved and branching so as to intersect near the surface, and 
thus cut off Superficial cell-masses of the most irregular shapes 
and mes. There is apparently the greatest irregularity in the 
Srentation of the cleavage planes both with reference to each 
other and 
the fiour to the surface of the dividing mass, as a glance at 
bes i, referred to above will show, and as I have described 
Cleava Ae ie scape of Fuligo. As this method of progressive 
the ie _ is of wide occurrence among the thallophytes, 
ie "a e of Tectangular intersection loses that universal 
fo division upon which Sachs so strongly insisted. 
. we vase of rectangular intersection so as to further 
Sion to . meister’s doctrine of the subordination of cell divi- 
Tesults ie of organisms as wholes, and in this sense his 
theoretical] anor the “asked part, been taken up and utilized for 
its division purposes in discussions on the nature of the cell and 
the oa : a 26). With Hofmeister, Sachs consider? 
elops “eis point of such a structure as the pine shoot 
Stow} ply as a mass of protoplasm analogous to that at 
"98 end of a Vaucheria filament. The shape of the end 
