I find that Gregory (Proc. Roy. Soc. B.
, Vol. 84, p. 14) has made the necessary crosses and proved that coupling takes place in each sex. The exact form of the coupling, however, still remains somewhat uncertain.Primula sinensis
appears to be a somewhat difficult type for such a determination. Upon the whole, the evidence clearly points to the occurrence in this case of the 2: 1: 1: 2 ratio in each sex.Google Scholar