396 
Multiple factors, 219-261 
Mutation, 35 
Myxine, 95 
N 
Nabours, 69, 209 
Nachtsheim, 140 
Nematodes, 174 
Nicotiana alata grandiflora, 232 
Nicotiana forgetiana, 230-231 
Nightshade, 26, 177 
Nilsson-Ehle, 225-226 
Non-disjunction, 193, 199 
Oo 
Oenothera, 26 
Oenothera gigas, 175-176 
Oenothera lamarckiana, 175, 193 
Oenothera lata, 193 
Oenothera semilata, 193 
Opalina, 305 
Operculina, 305 
Orchestia, 94 
Oudemanns, 116 
P 
Paramecium, 284, 285, 295, 296, 
299, 302 
Pascher, 306-307 
Parasitic castration, 114-116 
Paratettix, 209-210 
Parthenogenesis, 97 
Pea, 26, 69 
Pea comb, 270 
Pelargonium, 185-186 
Peltogaster, 114 
Petromyzon, 95 
Phalangium, 94 
Phillips, 250 
Phragmatobia, 88-90 
INDEX 
Phylloxerans, 101-105 
Pigeons, 69-70, 233, 240 
Pinney, 154 
Plastids, 182 
Plough, 68, 77 
Polarity, 76 
Polytoma, 97 
Polar bodies, 163 
Porthetria (see Lymantria) 
Potato beetle, (see Leptinotarsa) 
Potency, 254 
Preformation, 277 
Presence and absence, 275 
Primula, 38-39, 69, 77, 176, 194 
Pristiurus, 158-160 
Protozoa, 282-306 
Punnett, 5, 113, 168 
Pygera, 188 
R 
Rabbits, 204-205, 235, 240, 269 
Rats, 69, 280 
Reduplication, 74, 168 
Reversible mutations, 206 
Rhabdonema, 96 
Root, 294 
Rose comb, 270 
Rosenberg, 154 
Rotifer, 97 
Roux, 77, 278 
Rudimentary, 34-35 
8 
Sacculina, 114 
Schleip, 96 
Schmitt-Marcel, 106 
Schreiner, 95 
Sea-urchin, 106, 143, 147, 149 
Sebright, 107 
Secondary sexual characters, 106- 
116 
