FORMATION OF THE FIRST SPERMATOCYTE CHROMOSOMES 581 



The fact that two methods of ring formation are present in 

 Forficula might lead us to suspect that two methods of conju- 

 gation may be present or that we have some of the spermatocyte 

 chromosomes dividing reductionally in one division and some in 

 another. However, I cannot say definitely whether such is the 

 case, as in ring formation by the opening up of the two parts of 

 a longitudinally split thread, it is impossible to say exactly where 

 the division occurs in the ring. Presumably it occurs where 

 the ends of the double thread remain attached, but this is un- 

 certain since all indications of this point of juncture are lost in 

 later stages of condensation (plate 1, figures 8 to 11). Also 

 it is impossible to say whether the cross division in such figures 

 as shown in plate 1, figure 18, is reductional or equational, since 

 it is not clear whether the chromosomes have conjugated end to 

 end or side by side. 



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