120 AMPHIMIXIS OR ESSENTIAI MEANING OF [XII. 



divisions, which are togetherspoken of as the 'reducing divisions,' 

 generally take place after the ^gg has been laid or has, at any 

 rate, left the ovary. This probably explains, as I have already 

 maintained, why the division is so unequal, and why all the 

 daughter-cells cannot become ova, but only the largest of them, 

 viz. that one which alone contains the food-material necessary 

 for the building up of the embryo. 



Fig. II. 

 Formation of ova in Ascaris rnegaloccphala, var. hivalens. 



In other respects the formation of the polar bodies corres- 

 ponds with the two divisions of the mother-cells of sperma- 

 tozoa : in both cases there are two successive cell-divisions, 

 and furthermore in the ^gg both daughter-cells of the first 

 generation divide again— not only the larger one, the ovum, but 

 also the smaller or first polar body — for it is well known that 



