472 ELMER L. SHAFFER. 



PLATE VIII. (Fics. 71 TO Si). 



FIGS. 71, 72. Portion? of the nurse chambers of the ovaries, showing fibrous 

 appearance of central plasmatic mass in which the egg-strings of the oocytes end. 

 Nurse-cells in various stages of ingestion may be seen and the products of their 

 disintegration may be seen passing down the egg-strings into the oocytes. The 

 oocytes are distinguishable by their deeply staining perinuclear zone of mito- 

 chondria. 



Figs. 73 to 75 are various stages of synapsis in oocyte. 



FIG. 73. Protobroque nucleus at beginning of synaptic period. Two chromatic 

 nucleoli are present. 



FIG. 74. Deutobroque nucleus of oocyte. Treads become more evident; 

 two chromatic nucleoli are present. 



FIG. 75. Leptotene stage. Polarization of the threads. Chromatic nucleoli 

 are absent. 



FIG. 76. Pachytene bouquet stage. 



FIG. 77. Section across bouquet stage, showing 20 threads on end view. 



FIG. 78. Strepsistene stage. Reappearance of the two chromatin nucleoli. 



FIG. 80. Oocyte from ovaries fixed in Bourn's fluid (10 hours) showing effect 

 of acetic acid on mitochondria. Vacuoles, globules and nucleolar-like structures 

 are found in cytoplasm due to the partial dissolution and agglutination of the 

 mitochondria. 



FIG. 81. Oocyte after fixation in Benin's fluid for six hours, showing perinuclear 

 zone of mitochondria only partially destroyed. Two chromatin nucleoli are 

 present in the nucleus. 



