INDEX 



219 



Single comb, 29 

 Size, inheritance of, 164 

 . Species, nature of, 181 



origin of, 10 

 Spermatozoa, 3 

 Sports, 179 



Staples-Browne, R. , 61 

 Sterility, 182 



in sweet-peas, 115, 131 

 Stocks, double, 153 



hoariness in, 50 

 Sweet-pea, colour in, 41, 74 



history of, 'jj 



sex in, 114 



size in, 57 



sterility in, 115, 131 



Telegohy, 197 

 Thrum-eye in primulas, 51 

 Toe, extra toe in poultry, 70 



Tortoiseshell cats, lop 

 Tschermak, E. , 26 



Unit-characters, 28 



Variation, 13 



Vigour, increased from cross, i65 



Walnut comb, 29 

 ^Weismann, A., 12 

 Wheat, beard in, 69 



experiments with, 188 

 White, in poultry, 67 

 Wilson, J., 198 



X chromosomes, 103 



Y chromosomes, 103 

 Yellow mice, 150 



Zygotes, nature of, s 



THE END( 



Printed by R. & R- Clark, Limited, Edinburgh. 



