226 BOTANICAL GAZETTE [OCTOBER 
We may return now to the further consideration of the cleav- 
age processes by which the aethalium is cut up into spores, 
We have noted above that the primary cleavage furrows cut into 
the surface of the protoplasmic mass at varying angles, that they 
may be curved, may branch, etc., in the most irregular fashion, 
with no reference whatever to the distribution of the nuclei 
This much of regularity, however, can be seen. The furrows 
are so oriented with reference to each other and to the surface 
of the mass that cleavage at first progresses more rapidly at the 
Surface than in the center. Thus, one or more layers of very , 
irregular one- to several-nucleated segments are cut off on the 
periphery, while the central mass has been cut through by only 
a few furrows. What is true of the exterior of the aethalium as 
a whole is also true of the surfaces of the interprotoplasmic gaps 
or lacunae. It can be seen from jig. 2 that the surface of each 
such lacuna is lined by a layer of one- or few-nucleated seg 
ments, while beneath them larger multinucleated segments are 
found. The peripheral segments are very irregular in shape, 8 
are also the larger central segments. Frequently broad thia 
plates are found; elongated sausage-shaped masses are also 
common. As noted above, the cleavage planes follow no such 
simple rules as cutting through the short axis of the mass yee 
divided, or always dividing a mass successively in planes th 
intersect at right angles. Hofmeister’s law, also, that cell oe 
sion always occurs transversely to the axis of most ia 38 . 
growth, has no application here, since no growth is taking ae : 
at the time when these divisions occur. ,3 i 
If we study the cleavage of any one of these central m << 
of protoplasm we shall find the orientation of the furrows - 
tially similar to that of those which cut in from the Bee is 
the entire mass. Fig. 5 shows such a mass with its yee the 
the equatorial plate stage, both polar and profile views : 4 
latter being shown. It is to be especially noted also that # ‘ 
furrows in Jig. 5 are not directly continuous with - seg : 
appeared first on the surface of the mass from which ee 
ment in question was taken. No single furrow can be 
