154 AMPHIMIXIS OR ESSENTIAL MEANING OF [XII. 



much further advanced in some of the germinal vesicles examined 

 than it was in others. Half the number of 48 or 52 idants in the 

 equatorial plate pass to one, and the other half to the other pole. 

 If a diminution in the ids be characteristic of a ' reducing divi- 

 sion,' it follows that this term can only be applied to the process 

 which has just been described in Artemia, if the whole number 

 of 48-52 idants have arisen directly from the primary chromatin 

 granules: if, on the other hand, only 24-26 idants were so 

 derived, and the equatorial plate was at first composed of a 



OCL 



3b 



© ® © @ © 

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Fig, IX. 



Artemia. Germinal vesicle of the parthenogenetic ^g^ before and during 

 polar division : partially diagrammatic, from my own preparations. 



I. Numerous chromatin granules scattered through the w^hole thick- 

 ness of the germinal vesicle. 2. Numerous chromatin granules (115) 

 collected in the equatorial plane. 3 a. The same arranged in a double 

 wreath of 52 idants in the polar spindle. 3 6. A part of the double 

 wreath with the separate idants indicated by letters. 



single wreath which was subsequently doubled by division ot 

 the idants, it would follow that the process would be an ' equal 

 division.' In the latter case, the two idants lying over each 

 other would be identical, i. e. composed of similar ids, and 

 identical idants would pass into each daughter-nucleus. If, 

 however, as in the former supposition, the two adjacent idants 

 were independently derived, and therefore composed of dif- 

 ferent separate ids (chromatin granules), it is clear that the 



