PART I. KARYOKINESIS. 



CONTENTS. 



lutroduction 

 Methods 



I. Maturation. 



A. Prerlivision Stages . 



1. The Ovarian Egg 



2. Egg Laying 



B. ^laturation Divisions 



1. Nuclei .... 



a. Chromatin 



b. Nuclear Sap 



c. Nucleolus . 



d. Chromosomes 



2. Centrosoraes and Central Spindles 



3. Polar Rays, Spindle Fibres and Spheres 



4. Polar Bodies 



II. 



Fertilization. 



1. Entrance of Spermatozoon 



2. The Germ Nuclei .... 



3. Egg and Sperra Asters and Spheres 



4. Approach of Germ Nuclei and Spheres 



5. Origin of Cleavage Centrosomes 



III. Cleava(;e. 



1. Nuclear Changes during Cleavage .... 



a. Independence of Germ Nuclei . , . . 



b. Chromatin ..... ... 



c. Separation of Chromosomes and Formation of Daughte: 

 Centro.somes and Central Spindles 



a. Centrosomes ....... 



b. Central Spindles . . . ■ . 

 Polar Rays and Spindle Fibres; ]Mid-Bodies 

 Spheres ....... 



2. 



Nucle 



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IV. General Considerations and Comparlsons. 



1. The Nucleus during the Cycle of Division . . . . 



a. Formation of Chromosomal Vesicles; Growth of Daughter Nuclei 



b. Chromatic Differentiation ; Solution of 0.\ychromatin and Nuclear Merabran 



c. Escape of Nuclear Substances ; Aster and Spindle Formation 



d. Chromatic Elimination ..... 



2. Centrosomes and Central Spindles .... 



a. Structure and Metamorphoses 



b. Relation of Centrosome to Cell Body and Spliere 



c. Relation of Centrosome to Nucleus 



d. Comparisons ....... 



e. The Centrosome as a Persistent Cell Organ 



f. Homology of the Centrosome .... 



3. Spheres, Idiozome, etc. . ..... 



4. Archoplasm, Kinoplasni, etc. ..... 



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