CONTENTS. 



CHAPTER I. 



Introduction 



Size, Form and Appearance of Protozoa . ...'... 26 



A. Form-relations of Protozoa 30 



B. Protoplasmic Structure . 39 



CHAPTEE II. 



The Fundamental Organization. 



I. Nuclear Substances and Structures of the Fundamental Organization 49 



1. Chromatin . . 54 



2. Other Substances of the Nucleus 57 



Intranuclear Kinetic Elements 60 



(a) Endobasal Bodies 60 



1. Large Homogeneous Endobasal Bodies til 



2. Endobasal Bodies With Centrioles 63 



3. Nuclei With Pole Plates and Without Endo- 



basal Bodies 65 



II. Cytoplasmic Elements of the Fundamental Organization ... lis 



1 . Chromidia 69 



2. Volutin Grains 72 



3. Mitochondria 73 



1. ( iolgi Apparatus 77 



5. Silver Line System so 



CHAPTER III. 



Derived Organization. 



I. Cytological 83 



A. Derived Nuclei and Derived Nuclear Structures .... 84 



1. The Formation of a Nucleus 84 



2. Multiple and Dimorphic Nuclei 84 



3. Nuclear Derivatives During Division 88 



(a) Origin of Chromosomes and of Intranuclear 



Spindles at Division ... 88 



lb Origin of Fertilization (Meiotic) Chromo- 

 somes 100 



B. Derived Organization; Cytoplasmic Changes . . 104 



1. Cytoplasmic Chromatin . ... 104 



2. Cytoplasmic Kinetic Elements 104 



.'••/."■ 7 



