414 KING. [Vor. XIX. 
logical continuity of the chromosomes is maintained; and it 
is very probable that there is a linin connection between the 
chromatin granules during the early maturation stages which 
I overlooked in my previous work. When opportunity offers 
I shall collect new material showing the formation of the first 
polar spindle in the egg of Bufo, in the hope that with some 
new method of fixation or of staining I can follow the history 
of the chromatin granules and thus trace the chromatin con- 
tinuously from the early growth stages of the oocytes through 
to the maturation spindle. 
As far as I am aware, no investigator of amphibian 
oogenesis has as yet traced the chromosomes from the ovarian 
egg directly into the maturation spindle. Schultze, Carnoy 
and Lebrun, and Fick believe that the chromosomes of the 
polar spindles are derived from chromatin nucleoli which 
escape dissolution at the time that the germinal vesicle disin- 
tegrates. Other investigators have tacitly assumed that the 
chromosomes of the ovarian egg pass over into the maturation 
spindle and they have not given any figures of the critical 
stages. 
Since there are two periods in the development of the egg 
of Bufo when it is impossible to follow the changes which 
the chromatin undergoes, it is a difficult matter to decide 
when and how synapsis occurs. The first period when the 
history of the chromatin is obscured is during the synizesis 
stage in the young odcyte when the nuclear contents become 
massed together as shown in Fig. 25 and the chromatin ap- 
pears in the form of exceedingly fine granular threads. This 
stage is succeeded by one in which the chromatin, which is to 
form the chromosomes, is in the form of an apparently con- 
tinous spireme. Later this spireme splits longitudinally and 
then divides transversely forming the somatic number of sep- 
arate segments. Assuming that the chromosomes maintain 
their individuality during synizesis, it is obviously impossible 
to determine how they were joined together in the spireme 
which is formed after the synizesis stage. If the chromosomes 
were joined end to end, then the splitting of the spireme shown 
