Half of its gametes, therefore, will contain R and the other half will be without it (r).
They are not gametes but retain the double structure of the maternal cells.
The result of the meeting of these two series of gametes is given in Fig. 24.
IX, X, show the formation of the zygote by fusion of the nuclei of the gametes.
Is sex determined at the act of conjugation of the two gametes?
What, it may be asked, is the relation of these facts to the general principle that inheritance is through the gametes?
The gametes show every gradation from complete similarity (isogamy) to a condition like that of Cutleria.
Further, the segregation of the gametes does not appear to be so complete as the above hypothesis requires it to be.
Hence the inference that there is such a splitting of the gametes in the sexual act seems a legitimate one.
This problem reduces itself simply to that of the method whereby the gametes transmit heliotropism to the larvae or to the adult.