POLARITY AND BILATERALITY OF THE ANNELID EGG. 



FIG. 3. Maturation and first division of hyaline fragments of the eggs of Ch&top- 

 tertts, obtained by centrifuging before fertilization, a, outline of normal egg for 

 size-control ;/", outline of normal two-celled stage for size-control ; b, c, d, e, g, and 

 h, hyaline fragments of various sizes from a single experiment ; ?', a similar fragment 

 from another experiment. Fragment contains a small quantity of yolk. 



The eggs break apart along the planes of stratification with a high centrifugal 

 force, and further subdivision may occur so that the fragments are variable in size. 



It will be noted that the polar globules are abnormally large in the fragments (cf. 

 Fig. y, control). The proportions of the first two cells are, however, approximately 

 normal, Figs, g , h, i (cf. /, control). 



All figures drawn with the camera at a magnification of 780 diameters, and 

 reduced one half. 



