CONTENTS

CHAPTER I
MENDELIAN SEGREGATION AND THE CHROMOSOMES

PAGB

Introduction.    The Groups of Linked  Factors and the Chromo-

somes..........................       1

The Inheritance of One Pair of Factors...........       8

The Inheritance of Two or more Pairs of Factors   ......     20
 

CHAPTER II                                 ^^^^^M

TYPES OF MENDELIAN HEREDITY                        ^^^B

Dominance and Recessiveness...............     27       T^M

Manifold Effects of Single Factors.............     32        l^

Similar Effects Produced by Different Factors........     36

Modification of the Effects of Factors...........     38

I. By Environmental Influences............     38

II. By Developmental Influences............     42         ^^

III. By the Influence of Other Factors.........   .     45        ^H

'^■"".................... ""    I

CHAPTER III

LINKAGE

Examples IUustrating "Coupling"...............     48        ^^H

Examples Illustrating "Repulsion"..............     51        ^H

Examples of Different Frequencies of Crossing Over.......     52        ^H

The Mechanism of Crossing Over...............     59        T^Ê

Double Crossing Over....................     62

The Principle of Interference.................     64

The Linear Arrangement of Factors shown by Linkage Relations   .     64

Linkage in Other Animals and in Plants............     70

The Reduplication Hypothesis................     74

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