CONTENTS 



XI 



CHAPTER V 



The Chromosomes ...... ^ 



A. The Continuity of the Chromosomes 



B. The Composition of the Chromosomes of Smaixer Units 



C. Variation in the Number of Chromosomes . 



1. Variation in Chromosome Number due to Fra/j^mentation 



or Liiika^re 



o • • • . • 



2. Variatio7i in Chromosome Number due to Irrarularities 



of Mitosis 



3. Variation in Chromosome Number due to Multiplication 



or Fusion ..... 



HA<iE 



'-3 



124 



134 



13S 



'39 



144 



'47 



CHAPTER VI 



Heredity and Morphogenesis . . . . . 



A. The Equality of Inheritance from Male and Female 



Parents ...... 



B. The Process of Mitosis and its Implications. Thi 



Functional Differentiation of the Chromosomes 



C. The Process of Meiosis 



D. The Parallel which exists between Chromosome Be 



haviour and the Results of Breeding Experiments 



1 . The Genetics of a Tetraploid Plant 



2. Segregation a?id Parthe7iogenesis 



3. Segregation and Bud- Variation 



4. The Interchange of Hereditary Factors 



logons Chromosonies . 



5. The Cytological Basis of Mutation 



E. Sterile and Partially Sterile Hybrids 



F. The Nucleus in Morphogenesis 



G. Chromidia and Chondriosomes 



1. CJiromidia 



2. Chondrioso?nes . 



3. The Relatio7i between Chromidia and Chondriosomes 



bcticccn Homo 



153 



'54 



162 



167 



168 

 I 70 



171 

 172 



174 

 180 



1S3 



187 



190 

 190 



195 

 200 



