402 GEORGE T. HARGITT 
to yolk, as Jorgensen (’10) in sponges, Schaxel (10, 711) in various 
Hydrozoa and in Ascidia.° Nowikoff (’09), in Haliotis tubercu- 
lata tissue cells, found the nuclear chromatin assembled into 
1eleoli, worked over there and extruded into the cytoplasm in 
the term of chromidia. 
The dezeribed behavior of the nucleolus is also characteristic 
of other forms of the Coelenterata since Trinci (’06) found, in 
members of the farmliy Eucopidae, the nucleolus dividing into 
many and variously formed bodies in constant transformation. 
Merejkowsky (’83) saw the same thing in Obelia, as I have also: 
Wulfert (’02) noted similar conditions in Gonothyraea, as did 
Bergh earlier. On the other hand, Harm (’03), in Clava squa- 
mata, and C. W. Hargitt (’06) in Clava leptostyla, say the nucleo- 
lus sometimes migrates bodily into the cytoplasm. The latter 
believes the nucleolus has nothing to do with yolk formation. 
c. History of the nucleus in the germ cells. . When the egg cells 
are first distinguishable the nucleus is characterized by the pres- 
ence of a chromatin skein. This skein appears to be a series of 
chromatin loops, more or less centralized at one \pole of the nu- 
cleus (figs. 2 to 4), a condition similar to that found by Bigelow 
(’07) in eggs of Gonionemus and by the author (’09):in Tubularia 
crocea. In both these cases the arrangement occurred 1 oocytes 
after the last oogonial division and at the stage just before growth 
started; the author interpreting this as the synaptic stage or 
period of the conjugation of the chromosomes, which} as Mont- 
gomery (’04) says, takes place in metazoa in the early portion of 
the growth period of both oocytes and spermatocytes. Certainly 
in the cases just cited, this condition was not a prophase of divi- 
sion, and in Campanularia flexuosa, although no divisions have 
occurred previously, this condition of the chromatin does? not lead 
to division, and at the proper time the reduced number of ehromo- 
somes appears in the first maturation spindle. It seems sa‘fe to 
interpret this condition, therefore, as the stage of the ‘reduction,’ 
so-called. ‘ 
The next stage in the egg is that of the migration of the egg into’ 
the gonophore, a stage marked by certain peculiarities of the nu- 
cleus, as well as of the cytoplasm. The loops of chromatin very 
