446 KING. [VoL. XIX. 
same since they undergo a resolution into plasmosomes and ~ 
oxychromatin granules (Figs. 21-25). | 
The continuous spireme found at the stage of Fig. 9 ap- 
pears granular and somewhat irregular in outline. It does 
not undergo a longitudinal splitting at any stage of develop- 
ment, but it divides transversely into a number of segments 
which are of various lengths (Figs. 10-14). These segments 
are scattered throughout the nucleus and they are never found 
in pairs. Camera drawings of all of the sections of a nucleus 
in this stage of development show that the number of chro- 
matin segments is greater than the somatic number (24). All 
of the chromosomes appear granular, as a rule, and numerous 
fine projections extend out from either side (Fig. 16); only 
in rare instances (Fig. 20) do any of the chromosomes assume 
the feathery appearance which characterizes the chromosomes 
in the later growth stages of the ovarian ova. In later de- 
velopment all of the chromosomes break up into minute 
granules which are dissolved in the karyoplasm when the egg 
degenerates. 
Usually the cells begin to divide by amitosis soon after the 
spireme has broken into segments. Nuclear divisions some- 
times follow each other rapidly, and a cell may contain several 
rounded nuclei before the cytoplasm divides (Fig. 31). Asa 
rule, the largest nucleolus divides once or twice before the 
nucleus itself divides. A constriction appears in the middle of 
the nucleolus (Fig. 11), and it subsequently breaks into two 
rounded portions which are nearly equal in size (Fig. 12). 
The two nucleoli thus formed usually move to opposite sides 
of the nucleus before the nucleus divides (Figs. 10,13). The 
nucleus elongates considerably previous to amitosis (Fig. 15), 
and it is constricted into two nuclei of approximately equal — 
size (Figs. 16, 17, 19). Each nucleus contains at least one 
large nucleolus and apparently half of the chromosomes (Fig. 
19); and one or both of the nuclei may divide again before the 
cytoplasm of the cell shows any evidence of a division (Fig. 
31). Amitosis is frequently seen in the cells of Bidder’s organ 
in tadpoles killed at the time of metamorphosis, and it can be 
