PARTHENOGENETIC CLEAVAGE OF THE ARMADILLO OVUM. 53 



have to do with the reorganization of the cytoplasmic materials 

 of the ovocyte. In this respect, and probably in many others, the 

 armadillo bears a marked resemblance to the marsupials, espe- 

 cially Dasyurus, the Australian native cat, whose early develop- 



g?, 



TEXT-FIG, i. A full-grown ovocyte, showing cytoplasmic organization, etc. 

 Deutoplasmic zone (dz), formative zone (fz), germinal vesicle (gv), zona pelucida 

 (zp) (X 410). 



dz 



TEXT-FIG. 2. 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 (/>s) lies in a tangential position at the equator of the ovocyte. 

 Deutoplasmic granules (dg) lie in the center of the deutoplasmic mass. The zona 

 pelucida (zp) is a dense envelope, without radiations. 



ment is so ably described by Hill (1910). So close is this re- 

 semblance that any description given for one species would 

 apply in almost every detail to the other. 



