Heredity and sex . Irameks C? a d a Fig. 106. — Diagram to show the heredity of the lethal factor (carriedby black X). A, red-eyed female, carrying the factor in one X, is bred tonormal white-eyed male. B, her red-eyed daughter, is bred again to a normalwhite-eyed male, giving theoretically the four classes shown in C, but one ofthe classes fails to appear, viz. the red-eyed male (colored black in the dia-gram). The analysis (to right) shows that this male has the fatal X. Oneof his sisters has it also, but is saved by the other X. She is the red-eyedfemale. If she is bred to a white-eyed male
Heredity and sex . Irameks C? a d a Fig. 106. — Diagram to show the heredity of the lethal factor (carriedby black X). A, red-eyed female, carrying the factor in one X, is bred tonormal white-eyed male. B, her red-eyed daughter, is bred again to a normalwhite-eyed male, giving theoretically the four classes shown in C, but one ofthe classes fails to appear, viz. the red-eyed male (colored black in the dia-gram). The analysis (to right) shows that this male has the fatal X. Oneof his sisters has it also, but is saved by the other X. She is the red-eyedfemale. If she is bred to a white-eyed male, she gives the results shown inD, in which one class of males is again absent, viz. tlie red-eyed male. Inthis diagram the black X represents red eyes and lethal (as though completelylinked). SPECIAL CASES OF SEX-INHERITANCE 223 mosome that each red male contains is one of the twochromosomes present in the original red-eyed grand-mother. If this chromosome contains a factor whichif present causes the death of th
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Keywords: ., boo, bookcentury1900, bookdecade1910, booksubjectsex, bookyear1913
