466 ELMER L. SHAFFER. 



PLATE V. (Fics. 35 TO 43). 

 Synaptic Stages in the Oocyte. 



FIG. 35. Nucleus of very young oocyte at beginning of growth period. Chro- 

 matin in form of a delicate network; two chromatin nucleoli are present (Proto- 

 broque nucleus). 



FIG. 36. Deutobroque nucleus. Chromatin beginning to loose net-work ap- 

 pearance and individual threads become recognizable; two chromatin nucleoli 

 present. Mitochondria in crescentic area closely applied to nuclear membrane. 



FIG. 37. Leptotene stage. Polarization of threads; chromatic nucleoli absent 

 Mitochondria spreading around nucleus. 



FIG. 38. Zygotene stage. Leptotene threads are pairing parasynaptically. 

 Mitochondria completely surround the nucleus. 



FIG. 39. Pachytene stage. Bouin fixation, showing dissolution of mitochondria . 



FIG. 40. Pachytene bouquet stage. Macrochromosome loop recognizable 

 as largest loop. 



FIG. 41. Section across bouquet stage showing pachytene threads on end view, 

 20 in number. Bouin fixation, showing effect on mitochondria. 



FIG. 42. Release from bouquet stage; primary split evident in threads. Bouin 

 fixation, 10 hours, showing artefacts produced by dissolution of mitochondria. 



FIG. 43. Strepsistene stage. Synaptic threads separating and twisting about 

 each other; two chromatin nucleoli are again present. Mitochondria increasing 

 in numbers in perinuclear zone. 



