INDEX 



?>7^ 



Morgan, L. V., 36, 60, 91, 103 

 Morgan, T. H., 20, 22, 35, 82, 163, 242, 



265, 338 

 Mosaics, 191 



Mott-Smith, L. M., 348, 364 

 Mouse, 162 

 Mule, 274 

 Muller, H. J., 163, 205, 259, 262, 263, 



265, 338, 339, 347, 348, 354, 364, 3^5 



Multiple alleles or allelomorphs, 153, 

 154, 175, 181-182, 342 



Multiple factors or genes, 185, 223, 

 225 



Mutants, 322, 324 



Mutation, 165; gene mutations, 340- 

 365 ; method of identifying, 340- 

 341 ; frequency, 341 ; extent of 

 change, 342; usually recessive, 343 ; 

 place of occurrence, 344; time of 

 occurrence, 345-346; hidden, 343- 

 345; agents inducing, 347-349; so- 

 matic, 346; spontaneous, 348; re- 

 sulting from radiation, 347; from 

 high temperatures, 348 ; directed, 

 349-350; stability, 350-35S; rever- 

 sion, 350-354; unstable, 352-354; in- 

 constant, 352 ; injurious effects, 355 ; 

 inactivation of genes, 356; lethal, 

 356; dominant, 360; progressive, 

 360; resulting from chromosome 

 breakage, 333-335, 361; relation to 

 progressive evolution, 363-364 



Nachtsheim, H., 305, 314 



Near-sightedness, 98 



Nematodes, 80, 190 



Newman, H. H., 205, 257, 260-263, 

 265, 275, 281 



Night blindness, 98 



Nilsson-Ehle, H., 229 



Non-disjunction, 59, 81, 91, 317, 322 



Nucleus, 8, 42-43 



Number of chromosomes, 10, 38, 44; 

 changes in number, 59, 317-326; re- 

 duction, 50; in diflrerent species, 337 



Octopus, sex ratio, 76 



Oenothera, 319, 322, 324, 325, 336 



Oocyte, 47 



Oogonia, 47 



Orthogenesis, 349-350 



Ovary, 70 



Ovum, 6, 51 



Paracentrotus, 269-272 

 Parents and offspring, chromosomes 

 of, 21; resemblance, 299-301 



Parthenogenesis, 80, 309 



Patterson, J. T., 354, 364 



Peas, iq6, iri-113; chromosome map, 



162; linkage groups, 174 

 Permanence of recombinations, 307- 



314; of mutations, 350-354 

 Phaenotype, in 

 Phillips, J. C, 229 

 Phylloxera, 76, 82 

 Physiological characters, 100 

 Pigeon, sex ratio, 76 

 Plough, H. H., 350, 365 

 Polyploids, 325 



Population, constitution of, 298 

 Position effect, 335-336, 362 

 Positive reaction to light, 100 

 Primordial germ cell, 45 

 Primrose, 244, 304 

 Progressive atrophy, 98 

 Progressive evolution, 363 

 Progressive mutations, 360 

 Pronuclei, 38 



Protenor, chromosomes, 14 

 Protozoa, 287, 309 

 Psychological tests, 257-263 

 Pygaera, hybrids, 275 



Quantitative characters, 225 



Rabbit, 305-307 



Radiations, 326-329, 347-348, 354 



Rat, 162 



Ratios, Mendelian, 109-113; dihybrid 

 (two pairs), 114-119; trihybrid 

 (three pairs), 119; polyhybrid 

 (many pairs), 121; inheritance ra- 

 tios, 206-231, 289; exchange or 

 cross-over ratios, 141-151 



Reaction to light, 100 



Recessive characters, 28; inheritance, 

 29-32 ; in sex-linked inheritance, 94 ; 

 two in same individual, 132; domi- 

 nant offspring from recessive par- 

 ents, 132; recessive alleles, 132, 

 219; recessives not alleles, 220; re- 

 lation to weakness, 289-294 



Reciprocal crosses, 95 



Recombinations in inheritance, 283- 

 299; relation to transformation, 

 301-314 



Reduction of number of chromosomes, 



50 

 Reduplicated legs, 243 

 Relationship and similarity, 299-301 

 Resemblance of parents and offspring, 



299-301 

 Resting nucleus, 43 



