538 
somes, dividing and distributing them as accurately, and retaining among 
them the characteristic diverse forms and sizes always recognisable in 
the massive chromosomes during the anaphases of mitosis. The multi- 
nucleate Opalinas, on the other hand, neglect the chromatin masses, 
making no provision for their division or for the presence of even ap- 
20 216 
Figs. 14 to 21. Resting nucleus and mitosis in Opalina intermedia. X 1780 diameters. 
Fig. 14, a resting nucleus. Four masses of chromatin are seen clinging to the inside 
of the nuclear membrane. A more delicate network, also just beneath the nuclear 
membrane, is shown. The achromatic structures are not drawn. Fig. 16, a nucleus 
entering upon mitosis. One bit of massive chromatin is seen on this, the upper, sur- 
face of the nucleus, also numerous granules arranged in lines. Fig. 16, a nucleus in 
an early anaphase stage of mitosis. Fig. 17, an end view of a nucleus similar to that 
shown in Fig. 16 or Fig. 18. Fig. 18, a later anaphase. Fig. 19, a still later anaphase. 
The nucleus is beginning to constrict at the equator. Fig. 20, a very late anaphase, 
the two daughter nuclei being almost separated. Fig. 21, two daughter nuclei, a and b, 
in the resting condition. 
