IV CONTENTS. 



Color and its inheritance in guinea-pigs Continued. PAGE. 



Heredity of fur and eye color Continued. 



Color vs. white 64 



Intensity of general color development 64 



Dark vs. yellow color 65 



Variations of dark color 66 



Table of factor combinations 66 



Hereditary factors and the physiology of pigment 67 



Discussion of experiments 74 



Material 74 



Systematic position 74 



Description of stocks 74 



Problems 77 



Inheritance of dilution 77 



The red-eye factor 77 



Dilution 79 



The dilution factor 80 



Inheritance of minor variations in intensity 85 



Methods and accuracy of grading 85 



Variations in intense guinea-pigs and albinos 85 



Multiple allelomorphs 86 



The relations of imperfect dominance, stock, and age to grades of intensity . . 87 



Variations of yellow 89 



Variations of sepia 92 



Variations of eye color 93 



Summary 93 



Inheritance of variations in the agouti pattern 94 



Previous work 95 



The inheritance of the agouti of C. rufescens 96 



Minor variations 99 



The inheritance of the agouti of C. culleri 100 



Inheritance of rough fur 100 



Classification 102 



Previous work 102 



Material 103 



Problems 104 



Inheritance of rough as opposed to smooth 105 



Inheritance of major variations 106 



Possibilities of linkage among rough and color factors 113 



Summary of rough tables 115 



Minor variations 116 



Roughness of series II 117 



Summary 118 



General conclusion 119 



Experimental data 121 



Explanation of tables 62 to 137 121 



PART III. FURTHER STUDIES OF PIEBALD RATS AND SELECTION, WITH OBSERVATIONS 



ON GAMETIC COUPLING. BY W. E. CASTLE. 



PAGE. 



The progeny of hooded rats twice crossed with wild rats 163-168 



A second report on mass selection of the hooded pattern of rats 168-172 



Further observations on the mutant series 173-174 



Gametic coupling in yellow rats 175-180 



Tables 181-187 



BIBLIOGRAPHY 188-190 



EXPLANATION OF PLATES .. 191-192 



