104 



SEX INHEKITANCE 



Xx may remain in the egg and Xx' pass out; or, 

 in other eggs, Xx' may remain in the egg and Xx 

 may pass out. There will be, in consequence, two 



XxXx 



STEM nomER-rcrau: TRoDuciNc line 



I" GENERATION 



XxXx' 



STEM namen - male producing une 



XxXx 



POLAR SPINDLES 



STEM MOTHERS ECC5 



XxX) 



NlCifWWT - FEriALE FRODUCEff 



a-" CENOtATIOH 



XxX 



X' 



MJGRANT,- HALE PRODUCER 



XX XX' 



P0L4R SPINDLES 



mALE EGGS 



XxXx 



fEMALE 



3" GENERATION 



Xx 



rlALE-TYTE 1 



Xx' 



MALE-TTftn 



FErtALE PRODUCING 



POLAR SPINDLE 



Fig. 35. — Diagram to illustrate tho chromosomal cycle of Phylloxera 



carya3caulis. 



