. The physical basis of heredity . / Fig. 81.—First spermatocyte division a-c, and the second spermatocyte division d-f inthe hornet. (After Meves.) in that the second division produces two functionalsperms, both female producing. Since the male comes from an unfertilized egg, the ^^W^ rv7{//aeeaiiAi4. 0<5 Fig. 82.—^Life cycle of Phylloxera caryacauli SEX-CHROMOSOMES AND INHERITANCE 183 queen must transmit to him all her characters, thus givingrise to a form of inheritance that has a superficial resem-blance to sex-linked inheritance. A queen of a pure race,bred to a male of another
. The physical basis of heredity . / Fig. 81.—First spermatocyte division a-c, and the second spermatocyte division d-f inthe hornet. (After Meves.) in that the second division produces two functionalsperms, both female producing. Since the male comes from an unfertilized egg, the ^^W^ rv7{//aeeaiiAi4. 0<5 Fig. 82.—^Life cycle of Phylloxera caryacauli SEX-CHROMOSOMES AND INHERITANCE 183 queen must transmit to him all her characters, thus givingrise to a form of inheritance that has a superficial resem-blance to sex-linked inheritance. A queen of a pure race,bred to a male of another race with a dominant factor,produces daughters all showing the dominant characterof the father, and sons all showing the recessive characterof the mother. Since the son gets his entire chromosome-complex from his mother, he must necessarily be like her,whether the character in question is in the sex-chromo-some, or in some other one. •■ft^ ^ --—._-^. / :-^ # • M. ,. ■ ^%€- # a Fig, 83.—Extrusion of the polar body from a male-producing egg with Inj^ging chro-mosomes on the spindle, a; and extrusion of the polar body from a female-producingeggi b; in Phylloxera. In the phylloxerans there are two parthenogeneticgenerations followed by a sexual one (Fig. 82). In the sec-ond parthenogenetic
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectheredit, bookyear1919
