414 BOTANICAL GAZETTE [JUNE 
and chemistry. It would seem to be necessary to assume some 
sense of form in the organism which Mott has named “ morphaes- 
thaesia,’”’ a striving of the individual to attain a certain shape 
characteristic for the species. 
The apparently unequal division of the chromatophore attracted 
my attention, and in order to determine just what were the pro- 
portions of the dividing parts, I made 
careful camera lucida drawings of six 
individuals of C. Ehrenbergii in early 
stages of division. It will be seen 
from the text figure, which is a 
composite one made from these six 
sketches, that the chromatophore 
division results in a cone and a 
frustum, and that apparently the 
cone is much the larger. The cubic 
contents of these two solids can be 
approximately determined, however, 
and the rather surprising fact is 
revealed that the cone has certainly 
not more than two-thirds the cubic 
contents of the frustum. It must be 
remembered, however, that the frus- 
tum end includes half of the large 
nucleus and of the vacuoles on either 
side of it which do not appear in the 
cone end. This blunt end is also the 
one which must undergo reconstruc- 
tion, a process which undoubtedly 
uses up quite an amount of material 
such as starch, of which this portion contains more than the 
cone. However, it is plain that it would be improper to speak of 
this new half as “growing out,” in the sense that it has to grow 
in order to become as large as the pointed end. It contains at 
division as much, or probably more, material than the old end; 
there is a reshaping of this material, but both ends take part in 
the growth that is to produce again a normal size in the individual. 
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