THE OVUM OF THE NINE-BANDED ARMADILLO. 115 



moved to one pole and forms a cap of considerable density, 

 thick in the center and thinned out at the periphery. The 

 deutoplasmic mass (d.z.) occupies the opposite pole and is prac- 

 tically in contact peripherally with the ovocytic membrane. 

 The structure of this deutoplasmic material is represented in 



dz 



f- 



18 



FIG. 17. A full-grown ovocyte, showing cytoplasmic organization, etc. Deu- 

 toplasmic zone (dz), formative zone (fz), germinal vesicle (gi<), zona pelucida (zp) 



(X4io). 



FIG. 1 8. A maturing ovocyte, showing the new reversed polarity. The ovocyte 

 is placed with the animal pole upwards. The deutoplasmic zone (dz) occupies 

 the animal pole, the formative zone (fz) occupies the vegetative pole. The polar 

 spindle (ps) lies in a tangential position at the equator of the ovocyte. Deuto- 

 plasmic granules (dz) lie in the center of the deutoplasmic mass. The zona pelucida 

 zp) is a dense envelope, without radiations. 



