228 W. WALDEYER. 
readily seen with a lens, as small white spots or granules in 
the depression of the egg known as the fovea germinativa. 
O. Schultze established (conformably with the earlier state- 
ments of Gétte, Oellacher, and E. van Beneden, van Bambeke 
and others) that before impregnation the greater part of the 
germinal vesicle, together with the germinal spot and mem- 
brane, is distributed through the yolk—according to the figures 
of the author “distributed” is the best word; therewith 
undoubtedly a great bulk of the chromatin constituent dis- 
appears, asit at first divides into small particles, and ultimately 
becomes invisible. Scarcely any objection can be raised to 
the description of this process as a dissolution of the chromatin 
substance in the nucleoplasm or in the protoplasm. Since 
the greater part of the “solids” of the germinal vesicle 
becomes fluid and is disseminated through the egg-yolk, 
which itself is in part fluid, it may be said, I think, that the 
greater part of the nuclear substance mixes with the yolk- 
substance. All the older statements which were mentioned 
above, and which speak of a distribution (‘ Vertheilung ”’) of 
the germinal vesicle in the egg as its “disintegration” are 
therefore confirmed, and this seems to me, as O. Schultze also 
holds, a really very important point. 
But the whole of the germinal vesicle is not morpho- 
logically disintegrated and mixed with the yolk in this way,—a 
small portion persists morphologically, and, after the disappear- 
ance of the rest, consists of an achromatic spindle figure, with 
chromatic threads and roundish granules, which are arranged 
on the spindle, as in the karyokinetic division, at the pines of 
the so-called mother-star (Flemming). 
Further, a simple karyokinetic division of the spindle 
(Richtungsspindel of Biitschli) takes place. One portion of 
the nucleus remains in the egg-cell, and the other, together 
with a small portion of egg-substance, is extruded as the first 
directive corpuscle. Then the nucleus remaining in the 
egg again changes into a “ Richtungsspindel” (one can there- 
fore speak of a primary and a secondary “ Richtungsspindel”’), 
and in this way a second directive corpuscle is extruded, In 
