1896. ] NEW YORK ACADEMY OF SCIENCES. tit 
over one-half the diameter of the egg, a much greater ratio than 
that figured for Toxopneustes (12) wherein the length of the 
spindle similarly measured is seldom a third of the egg diameter. 
The reticulum occupying the interior of the centrospheres is ex- 
ceedingly fine and close. It stains very faintly with Hematox- 
ylin, though quite deeply with congo red. The centrosomes are 
now seen to be exceedingly near the outer peripheries of the 
centrospheres. In some preparations the surrounding darker 
area seems to have already faded away, in others it is dis- 
tinguishable (faintly it is true) not only in this stage, but dur- 
ing the early anaphase as well, though even then it soon disap- 
pears. In most cases no trace of rays can be detected within 
the centrospheres, though sometimes what appears to be a few 
short rays can be seen converging toward the centrosome when 
the latter is near the periphery. It is noteworthy that these ap- 
pear only when the centrosome is near the periphery, and that 
they occur on the outer side only of the centrosome. These 
rays, however, appear much finer than the astral rays and to re- 
semble in their staining properties the substance of the centro- 
sphere. The astral rays can be readily seen to branch out dis- 
tally and become continuous with the cytoplasmic reticulum, 
exactly as described by Wilson (10) in Toxopneustes. More- 
over the granular nature of the rays and of the cytoplasmic retic- 
ulum is clearly demonstrable. In these features they are ex- 
actly similar to the homologous structures in the maturation 
spindles. 
The splitting and divergence of the chromosomes now follow 
(Fig. 14), during which the centrosomes, undergoing no change 
save perhaps a slight further divergence of the daughter centro- 
somes, persist on the outer periphery of each centrosphere, as 
two dark staining granules. In this condition they remain un- 
til about mid anaphase, when (Fig. 15) a few rays may be seen to 
be focussed about each, making on the outer periphery of each 
centrosphere a minute and rather indistinct amphiaster. The 
old rays still persist. This amphiaster, as will be seen, is the 
precocious preparation for the second cleavage. 
The next stage (Fig. 16) shows the centrosomes further sepa- 
rated and with a small though well defined aster about each. 
The rays of these asters converge directly to the centrosomes 
with no certain trace of surrounding centrosphere. In this 
stage it would be impossible to distinguish the centrosomes 
were it not for the asters. The centrosphere now ellipsoidal in 
shape has been growing less distinct, its interior taking a darker 
stain and more nearly resembling the cytoplasm. Except in the 
region of the second cleavage amphiaster, it is still surrounded 
