GERM CELLS OF COELENTERATES 599 



The search for synapsis stages was long, exhaustive, and not 

 altogether satisfactory on account of the lack of success. Figures 

 3 and 4 may suggest synizeses or contraction phases, or they may 

 be spireme stages of oogonial prophases. The size of the cells, 

 approaching that of figure 2 and being smaller than the cells 

 of figures 5 and 6, which are certainly oogonia, suggests the 

 interpretation of this condition as an oogonial prophase. The 

 same thing is indicated by the number of loops in figure 4; there 

 were fourteen of these loops, so far as could be determined, 

 and this is so close to the diploid number of chromosomes that 

 it is probably sufficient warrant in itself for calling figure 4 a 

 prophase of an ordinary oogonial mitosis and not a contraction 

 phase. However, the arrangement of the chromatin in distinct 

 loops suggests the bouquet stage of early maturation phenomena. 

 The number of loops in such an interpretation would indicate 

 that a synapsis had not yet taken place. The position occupied 

 by these two cells (figs. 3 and 4) was on the border line between 

 the oogonial and oocyte zones. It seems probable that the size 

 of the cells is one of the most crucial bits of evidence and hence 

 these figures are merely phases in an ordinary oogonial division. 

 From this it follows that synapsis and synizesis stages are absent. 

 That this is not due to the material is clear, for the search was 

 diligent, the material abundant, the age of the gonads right for 

 the occurrence of such stages. 



From the conclusions of the above paragraph it follows that 

 figure 7 is the stage which comes next after figure 2, for figures 

 3 to 6 are merely oogonia, one of which (fig. 4) simulates a 

 synizesis stage. This seriation of stages is certain, as the size 

 of the cells demonstrates, and it is the most obvious conclusion 

 from a study of many gonads. When an entire gonad is under 

 observation there are a large number of cells like figure 2 near 

 the center of the gonad and many resembling figure 7 toward 

 the outer side. If a careful and exhaustive search reveal nothing 

 of synizesis or synapsis one might conclude that there is no 

 definite and precise series of chromatin changes which leads to 

 chromosome formation and reduction. Perhaps it would be 

 better to say no visibly definite and precise changes, since there 



