1079. Hybrid plants are generally sterile, or at least become so after a few generations. 'A mule plant may, however, be rendered fertile by the application of the pollen of either of its parents, in which case its offspring assumes the character of the parent by which the pollen was supplied.' (Lind. Introd. to Botany, 4th ed. (1848), vol. ii. p. 242.) Though, generally speaking, hybrids can only be obtained between nearly allied species, 'it is, nevertheless, said, that bigeners, that is to say, mules between different genera, have in some few cases been artificially obtained. Kolreuter obtained such between Malvaceous plants ; Gï¾µrtner, between Datura and henbane and tobacco; Wiegman, between a garden bean and a lentil ; and there are other cases. But all such productions were as short-lived and sickly as they were monstrous.' (Ibid.)
