Subject Index 



583 



Drosophila melanoga^ter (contin- 

 ued) 



haplo-IV, 415, 416 



heterochromatin in, 222, 223 



inheritance of sex in, 68, 69 



lethal mutations in, 236, 244, 245 



no crossing over in male, 152, 154, 

 162, 167, 186, 213 



nondisjunction in, 425, 4^6 



number of chromosomes in, 6, 26, 

 139, 147, 187, 424 



number of genes in, 16, 17, 147 



number of linkage groups in, 187, 

 189 



partial linkage map of, 187 



salivary gland chromosomes, 74, 

 75, 77, 398 



spacing of genes on chromosomes, 

 193 



spontaneous mutation in, 241 



superfemale, 249 



transplantation of tissues, 309 



triplo-IV, 416, 421 



triplo-X, 424 



triploid intersexes in, 482, 493, 496 



wild type, 17, 24fif., 148, 231, 

 307 ff., 335 



X chromosome, 68 ff., 96. 187, 

 189 £f., 196, 245 ff., 481, 506 



Y chromosome, 68 ff., 189, 481 

 Drosophila miranda, 524 

 Drosophila obscura, number of 

 chromosomes in, 187 



number of linkage groups in, 187 

 Drosophila pallidipennis, 223 

 Drosophila pseudoobscura, hetero- 

 chromatin in, 223 



heterosis in, 386, 387 



hybridization with D. miranda, 

 524 



intersexes in, 486, 496 



inversions in, 402 



number of chromosomes in, 187 



number of linkage groups in, 187 

 Drosophila simulans, heterochro- 

 matin in, 222 



intersexes in, 486 



Drosophila virilis, heterochromatin 

 in, 222 

 intersexes in, 485 

 miniature, 237, 239, 240, 337 

 mutable genes in, 237, 239 

 number of chromosomes in, 187 

 number of linkage groups in, 187 

 Drosophila ivillistoni, number of 

 chromosomes in, 187 

 number of linkage groups in. 187 

 Duodecaploid, 467 

 Duplex, 448, 461, 462 

 Duplicate genes, 330 ff., 342 ff., 

 353 ff., 371, 372, 385. 461. 464 

 Duplicate determiners, 354 

 Duplication, 209, 210, 264 ff., 394 ff., 

 414 



Ear-to-row method of selection, 378, 



379 

 Echinoderms, 523 

 Ectoderm. 302 

 Egg, 48. 49. 51, 66. 67, 68, 70. 78. 149, 



503. 504, 513 

 Elimination of chromosomes in 



Sciara, 489, 490, 491. 492 

 Elodea canadensis, 73 

 Embryo, culture of, 524, 525 

 Embryo sac, 51, 52, 392, 442, 541 

 Embryophyta, 503, 504 

 Endoderm, 302 



Endosperm, 52, 390, 438, 440, 442- 

 445. 514 

 abnormal in Iwbrids, 443, 444, 445, 



524, 525 

 as barrier to hybridization, 444, 

 524, 525 

 Environment, crossing over and, 167 

 effect of on development, 304 

 effect on gene mutation, 240, 241, 



243 

 effect on quantitative characters, 



376 

 effect on sex potentialities, 494, 



495, 510, 511 

 importance of, 30-32, 231, 301 

 isolating mechanisms and, 519 



