CHROMIDIA AND THE BINUCLEARITY HYPOTHESES. 287 
his two accounts. When he now desires to show that the 
secondary nuclei fuse and do not divide, he adduces as 
evidence—inter alia—the statements that “if the nuclei 
were dividing we should find dumb-bell shaped figures with the 
diameter of the nuclei drawn out at right angles to the plane 
of division. hisis not the case. . . . We should expect 
to find connecting strands of chromatin substance between 
the recently divided karyosomes . . . but no such con- 
necting strands exist. . . . We should expect to find the 
daughter-karyosomes elongated in the axis at right angles to 
the plane of division. . . . Such is not the case.” How 
TEXT-FIG. 3. 
Part of an Ameba proteus, containing “ chromidia ” (gametes 
of Allogromia). N. nucleus; Ch.“ chromidia.” (After 
Prandtl, ’07.) 
are we to accept such statements, when, to prove that the 
nuclei were dividing, he originally not only described 
but figured all these stages of which he now denies the 
existence ? (See Calkins, 705, Pl. 3, fig. 23.) So sure was he 
of this division that he even called it ‘“‘a modified mitosis,” 
and described the karyosome as a division centre, like the 
nucleolo-centrosome of Kuglena (text-fig. 25). 
As Prandtl (’?07a) has pointed out, Calkins’ ‘‘ gametes” of 
‘Amceba are probably the gametes of parasites allied to 
Allogromia, whose remarkable life-history Prandtl care- 
fully worked out. I cannot at all agree with Calkins in saying 
that if his secondary nuclei “ are parasites, then the secondary 
