Bacillus anthracis, unsegmented form, 71 Bacillus prodigiosus, variation in, 213 Bacteria, variation in, 212 Bacterium coli, variation in, 214 Baeolophus, geographical races of, 159 Barley, right and left-handed, 58 Basilarchia, geographical races of, 161 Begonia phyllomaniaca, 50 hybrids, 51 Bizarre Carnation, genetics of, 54 Black, as a variation from red, 148 Blackbird, varying, 150 Black Cock, fixity of, 28 Boarmia repandata, melanic form, 136 rhomboidaria, 137,139 Botrytis susceptibility to, 108 Bovidae, hybrid, 242 Brachydactyly, 89,95 Bradypus, vertebral variation, 68 Bud-sports geometrically irregular, 54-57 Buffalo, attempts to hybridize, 242 Bullfinch, gynandromorph, 45 Bulimus detritus, local variation of, 126 Canary, asymmetrical markings in, 154 Canidae, hybrid, 241 Capsella, 100 Cardamine pratensis, 239 Cat, Polydactylism, 53 Carnation, Picotees and bizarres compared, 54,58 Cataract, hereditary, 89 Certhiola, melanic, 142 Chladni figures, 60 Choloepus, vertebral variation in, 68 local variation in, 119 Cinerarias, self-sterility in, 238 Cistudo, local variation in, 119 Climatic varieties, 164 Coccaceae, variation in, 213 Coenonympha arcania, climatic forms of, 179 satyrion, 180 Coereba, melanic, 142 Colaptes, geographical races, 147 et seq. chrysoides, 154 Colloids, growth in, 65 Colorado beetles, experiments on, 218 Colour blindness in twins, 44 Continuous variation, possible example of, 173 Coracias, geographical races of, 160 Cotton, genetics of, 98,100