2 EISEN. [Vol. XVII. 



PAGE 



Chromioles i8 



Chromoplasm 22 



Chromomeres 23 



Leaders 25 



Chromosomes 26 



Chromoplasts and Endochromatic Granules 28 



Parachromatic Granules 34 



Linoplasts or True Nucleoli 34 



Linin 35 



Nuclear Membrane 37 



Phylogeny of the Nucleus 38 



Archosome 39 



The Archosome Proper : Its Structure, Centrosphere, Somo- 



sphere, and Centrioles 39 



Accessory Archosomes, their Structure and Functions. Expul- 

 sion of the Superfluous Accessory Archosomes 43 



IV. Spindles and Spindle Fibers 45 



General Remarks 45 



Mantle Fibers, Polar Fibers, and Central-Spindle Fibers 45 



Contractile Fibers 48 



Fiber Cones and Retractile Fibers of the Spindle Cones 49 



Spindle Bridge and Mid-Body 51 



V. Varieties of Resting Cells 52 



Polymorphous Spermatogonia 52 



Auxocytes 56 



Spermatocytes 59 



Spermatids 60 



VI. Mitosis 60 



A General Review of Mitosis. The Two Parallel and Inde- 

 pendent Processes of Evolution and Development : The 



Radiosomic and the Chromosomic 60 



The Radiosomic Process, or the Evolution of the Spheres, the 



Spindle, the Fibers, and the Formation of the Cell Wall 63 



The Chromosomic Process, or the Evolution of the Chromioles 



and their Formation into Chromomeres and Chromosomes 67 



Equation or Reduction 76 



Halting Stages in the Mitosis 76 



VII. The Structures of the Protoplasm 77 



Fibers, Granula and Alveoles 77 



VIII. Permanency of the Composite Structures of the Cell 82 



IX. Summary 84 



X. Nomenclature 90 



XI. Literature 97 



XII. Explanation of the Figures 100 



XIII. Stains, Fixatives, and Optical Apparatus 117 



