168 A. RICHARDS. 



EXPLANATION OF PLATE III. 



FIG. 17. Young oogonia, showing three sets of nuclei arranged in pairs. Only 

 one nucleolus is present in each, the large black granular masses being chromatin. 

 Cytoplasmic boundaries not well preserved. King, iron haematoxylin. 



FIG. 1 8. Oogonia; the upper nucleus stained very heavily. King, iron haema- 

 toxylin. 



FIG. 19. An oogonium beginning growth. King, iron haematoxylin and Bis- 

 marck Brown. 



FIG. 20. Mitosis in an oogonium just before the growth period begins. King, 

 iron haematoxylin. 



FIG. 21. An oogonium beginning growth; the chromatin is beginning to con- 

 dense in preparation for the synapsis stage. King, iron hsematoxylin. 



FIG. 22. Oogonium from the same ovary, slightly later in development. 



FIGS. 23-28. Progressive stages of synapsis, 23-26 from the same slide. King, 

 iron haematoxylin. 27, King, iron haematoxylin. 28, King, Ehrlich-Biondi. 

 In Fig. 26 are to be seen the beginnings of the yolk nuclei. They do not regularly 

 appear at this stage. 



