PLATE 6 



EXPLANATION OF FIGURES 



40 Portion of a germ gland of a larva 30 mm. long, showing the breaking up 

 of a cyst by the inward migration of follicle cells. 



41 A resting germ cell from a larva 42.5 mm. long. The gland was fixed in 

 Meves' solution and stained in iron hematoxylin. Mitochondria are abundant 

 in the cytoplasm. 



42 A germ cell in early prophase from a larva 30 mm. long. 



43 A germ cell in prophase somewhat more advanced than that in figure 42. 



44 Germ cell in middle prophase from a larva 47.5 mm. long. The chromatin 

 network has broken up and the individual chromosomes are free. Only one 

 nucleolus is present. 



45 Side view of a cell in which the chromosomes are arranged on the equa- 

 torial plate. 



46 End view of a cell in the same stage as figure 45. The individual chromo- 

 somes are still visible. 



47 Early anaphase in which a chromosome-like body lies outside of the 

 spindle. 



48 Early anaphase in which the chromosomes are migrating toward the poles. 

 Some of the chromosomes begin their migration earlier than others. 



49 A germ cell in late anaphase from a larva 27.5 mm. long. 



50 A germ cell in late anaphase showing a distinct midbody. 



51 Telophase showing reconstruction of the nuclei. One nucleolus has made 

 its appearance in each cell. 



52 An oocyte in the early synaptic phase, from a larva 77.5 mm. long. Mito- 

 chondria are numerous at this stage. 



53 Early leptotene stage from the same larva as the preceding figure. Both 

 astrosphere and vitelline body are present. 



54 Advanced leptotene stage from the same larva as the preceding figure. 



55 Synaptene stage (bouquet stage, synizesis stage), from a larva 59 mm. 

 long. 



56 Late pachytene stage from the same larva as the preceding figure. 



57, 58, and 59 Various phases of the diplotene-dictyate stage. The chromo- 

 somes are paired; chromatin-like bodies (chromidia) are found in the cytoplasm; 

 only one nucleolus is present. 



60 An oocyte in the early growth phase. The vitelline body is a prominent 

 structure at this stage. 



61 A growing oocyte sectioned through the surface of the nucleus, showing 

 the arrangement of the chromosomes in tetrads. 



138 



