CELL SIZE AND NUCLEAR SIZE Tea. 
2. The sizes of spindles, centrosomes, spheres and asters. The 
study of centrifuged eggs shows, as was observed in the case of 
normal eggs, that the sizes of spindles, centrosomes, spheres 
and asters are dependent upon the quantity of cytoplasm in which 
they lie. The size of the spindle is also related to the size of the 
nucleus, as I have already shown, but as this, in turn, is dependent 
upon the quantity of cytoplasm of the middle zone, it follows that 
the size of the spindle as well as that of the centrosome and sphere 
is related to the quantity of cytoplasm in which they lie. Fig. 
17 shows spindles in sister cells which are quite different in size 
owing to the different amounts of cytoplasm in these two cells; 
while figs. 11, 12, and 16 show centrosomes and sphere which 
vary In size depending upon the quantity of cytoplasm surround- 
ing them. 
In this connection attention should be called to the fact that 
the spindles from the stage of the metaphase to the end of 
mitosis are anchored in the cell, and can be moved only with 
much difficulty. The spindle fibers are tougher and more con- 
sistent than the surrounding plasm, and they are not a mere 
arrangement of granules in the lines of force as Lillie (09) has 
maintained for Chaetopterus. 
8. The rhythm of division in centrifuged eggs. The rhythm of 
division is not dependent solely upon nuclear size, nor cell size, 
nor the ratio of one to the other (Kernplasma-Relation), though 
it may be influenced by the absolute amount of cytoplasm present 
in the cell. Cleavage cells which contain a large amount of cyto- 
plasm, and which therefore have large nuclei, usually divide a 
little earlier than cells poor in cytoplasm, and with small nuclei, 
though this is not always the case, as is shown by fig. 17, in which 
the large and the small nuclei divide at the same time. Nuclei 
which differ greatly in size may still be in the same stage of the 
nuclear cycle, as shown in fig. 19, and may divide at the same 
time. On the other hand, figs. 25, 31, 34 and 37 show cases in 
which nuclei of the same generation divide earlier in cells rich 
in cytoplasm than in cells which are poor in this substance. 
4. Growth of cytoplasm at the expense of yolk. Centrifuged 
eggs afford an excellent opportunity of studying the way in which 
