Chapter I: Front Matter

INHERITANCE OF CHARACTERISTICS IN DOMESTIC FOWL.

BY

CHARLES B. DAVENPORT,

DIRECTOR OF THE STATION FOR EXPERIMENTAL EVOLUTION, CARNEGIE
INSTITUTION OF WASHINGTON.

WASHINGTON, D. C.
PUBLISHED BY THE CARNEGIE INSTITUTION OF WASHINGTON. 1909

CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION NO. 121.

PAPERS OF THE STATION FOR EXPERIMENTAL EVOLUTION, NO. 14.

PRESS OF J. B. LIPPINCOTT COMPANY PHILADELPHIA

TABLE OF CONTENTS.

PAGE

INTRODUCTION 3

CHAPTER I. THE SPLIT OR Y COMB 5
A. Interpretation of the Y Comb 5
B. Variability of the Y Comb and Inheritance of the
Variations 12

CHAPTER II. POLYDACTYLISM 17
A. Types of Polydactylism 17
B. Results of Hybridization 18

CHAPTER III. SYNDACTYLISM 29
A. Statement of Problem 29
B. Results of Hybridization 32

CHAPTER IV. RUMPLESSNESS 37

CHAPTER V. WINGLESSNESS 42

CHAPTER VI. BOOTING 43
A. Types of Booting 43
B. Normal Variability 43
C. Results of Hybridization 46

CHAPTER VII. NOSTRIL-FORM 59

CHAPTER VIII. CREST 67

CHAPTER IX. COMB-LOP 69

CHAPTER X. PLUMAGE COLOR 71
A. The Gametic Composition of the Various Races 71
1. White 71
2. Black 72
3. Buff 72
B. Evidence 72
1. Silkie × Minorca (or Spanish) 72
2. Silkie × White Leghorn 75
3. Silkie × Buff Cochin 76
4. White Leghorn × Black Minorca 77
5. White Leghorn × Buff Cochin 77
6. Black Cochin × Buff Cochin 78

CHAPTER XI. INHERITANCE OF BLUE COLOR, SPANGLING, AND BARRING 79
A. Blue Color 79
B. Spangling 80
C. Barring 81
1. White Cochin × Tosa 81
2. White Leghorn Bantam × Dark Brahma 82
3. White Leghorn Bantam × Black Cochin 82

CHAPTER XII. GENERAL DISCUSSION 85
A. Relation of Heredity and Ontogeny 85
B. Dominance and Recessiveness 88
C. Potency 92
D. Reversion and the Factor Hypothesis 93
E. The Limits of Selection 94
1. Increasing the Red in the Dark Brahma × Minorca
Cross 94
2. Production of a Buff Race by Selection 95
F. Non-inheritable Characters 96
G. The Rôle of Hybridization in Evolution 97

LITERATURE CITED 99

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INHERITANCE OF CHARACTERISTICS
IN DOMESTIC FOWL.

BY

CHARLES B. DAVENPORT.

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