CONTENTS 



XV 



III. 



1. Nuclear Segmentation. Mitosis (Flemming) ; Karyokinesis 



(Schleicher) 



(a) Cell division as it occurs in Salamandra maculata . 



First Stage. Preparation of the Nucleus for Division. 



Second Stage of Division 



Third Stage of Division 



Fourth Stage of Division 



(b) Division of the Egg-cells of Ascaris mcr/alocephala and 



Toxopneustes lividus ....... 



(c) Division of Plant Cells . 



(d) Historical remarks and unsolved problems concerning 



Nuclear Segmentation 



2. Direct Nuclear Division. Fragmentation. Amitosi* 



3. Endogenous Nuclear Multiplication, or the Formation of 



Multiple Nuclei 



Various methods of Cell Multiplication . 



1. General Laws ...... 



2. Review of the Various Modes of Cell Division 



In. Equal Segmentation 



16. Unequal Segmentation . 



lc. Cell-Budding ..... 



2. Partial or Meroblastic Segmentation 



3. So-called Free Cell Formation 



4. Division with Reduction 

 IV. Influence of the Environment upon Cell Division. Degeneration 

 Literature ........... 



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CHAPTER VII. 



The Vital Properties of the Cell .... 



Tbe Phenomena and Methods of Fertilisation 



I. The Morphology of the Process of Fertilisation . 



1. The Fertilisation of the Animal Egg . 



(a) Echinoderm Eggs .... 



(b) Eggs of Ascaris megalocephala 



2. The Fertilisation of Phanerogamia 



3. The Fertilisation of Infusoria 



4. The various forms of Sexual Cells ; equivalence of partici- 



pating Substances during the Act of Fertilisation ; Con- 

 ception of Male and Female Sexual Cells 



5. Primitive and Fundamental modes of Sexual Generation 



and tbe first appearance of Sexual Differences 

 II. The Physiology of the Process of Fertilisation 



1. Tbe Need of Reproduction of Cells 



(a) Parthenogenesis ..... 

 (/;) Apogamy 



2. Sexual Affinity ...... 



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>:> 7 

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