INDEX 



373 



Vesicles, chromosomal, 43 



Vigor in hybrids, 281, 291-293, 302 



W-chromosome, 58 

 Weakness, inherited, 100 

 Webbed toes, 128 

 Wenrich, D. H., 159 

 White eye, 29 

 Wild-type genes, 165 

 Wilson, E. B., 13, 19, 54, 339 

 Winchester, A. M., 354, 365 

 Winge, O., 127, 129 

 Witschi, E., 81 

 Wodsedalek, J. C, 274, 281 



X-chromosome, 14-22, 54; descent, 22, 

 83-87; relation to sex, 56-64; united 

 X's, 60, 91 ; relation to characteris- 

 tics, 83-103; defective, 84; abnor- 

 mal distribution, 90-93; role in de- 



velopment, 102-103 ; characters 

 dependent on, 98-101 ; mutations in, 



345 

 X-rays, 326, 347 



Y-chromosome, 19, 20, 22, 54, 56-58; 

 functions, 62, 123-128; relation to 

 characteristics, 122-129; occurrence, 

 123; descent, 123; in Drosophila, 

 123 ; activity in certain organisms, 

 124; relation to secondary sex char- 

 acters, 124-128; in plant, 128; in 

 man, 128; degeneracy, 128; ratios 

 and method of descent, 217-219; 

 crossing-over to X, 218 



Yellow body, 91 



Z-chromosome, 58 

 Zygote, 51, 53 



