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Charles E. Allen 
pole, it may be impossible to determine with certainty which, if either, 
is really a central body. Still, as has been said, in the majority of cases 
a single distinct body is present at or near the place just previously occupied 
by eacli central body; and it seems reasonably certain that the latter 
persists in every instance, although for the reasons given it becomes less 
conspicuous and its identification raore difficult. 
What has just been said of the behavior of the central bodies during 
the stages immediately following the swelling of the nucleus (Figs. 82, 
84, 86) applies equally to the later prophases (PI. VIII, Figs. 87, 88, 90; 
PI. IX, Figs. 93 — 96), the equatorial plate stage (Figs. 98, 99), the meta- 
phases (Fig. 101), and the anaphases (Fig. 102). During the telophases 
(Figs. 109 — 113, 115 — 122), the proportion of cases in which the central 
bodies are recognizable with reasonable certainty becomes even less. 
Sometimes the difficulty in identifying them seems to result from their 
lying verv close to the respective groups of daughter chromosomes (as 
at the lower pole in Fig. 112). In the cell sliown in Fig. 118, if the dark- 
stained body to the left of the upper nucleus is, as seems probable, a central 
body, it has plainly suffered considerable displacement, at least with refer- 
ence to the nucleus. Such a displacement is not surprising, in view of the 
changes in position which daughter nuelei in dividing plant cells have 
often been observed to undergo during the telophases; but if at all a 
frequent occurrence, it would evidently place another obstacle in the way 
of a certain identification of the central bodies. 
The behavior of the central body of Polytrichum is comparable in 
certain respects with that of the blepharoplast of Marsilia as described 
by Shaw (1898) and Belajeff (1899). According to Shaw, the blepharo- 
plast seems to be hollow, and, to judge from his figures, less deeply stain- 
ing, during the anaphases; and Belajeff finds that it becomes hollow 
and difficult to recognize at the equatorial plate stage. 
Woodburn (1911) figures several stages in the division of the an- 
drocyte motlier cells of Marchantia, which agree closely as to the appear- 
ance of centrosome-like bodies in the early prophases, their relation to 
spindle formation, and the relative difficulty of their observation in the 
later stages of mitosis, with what I find at eorresponding stages in Polyt- 
richum. It is unfortunate that Woodburn has not made a thorough 
study of the historv of the structures which have come under his notice. 
After the completion of cytokinesis (Figs. 123 — 125), the cytoplasm 
oFeach daughter cell (androcyte) contains a dark-staining granule, which 
is often (Fig. 125, upper cell of Fig. 124) the center of a few faintly- 
marked radiations. This body, as appears from a study of the metamor- 
