282 



GENERAL ZOOLOGY 



eff 



Fig. 169. — Diagram to illustrate the result of crossing a white-eyed yellow- 

 winged female with a red-eyed gray-winged male. Y, gray wing; y, yellow 

 wing; W, red eye; w, white eye. Y chromosome knobbed. {From Morgan, 

 Physical Basis of Heredity, J . B. Lippincott Company. By permission.) 



