Chap. XI. 



GKAFT-HYBRIDS. 



417 



was consequently propagated. Now it deserves especial notice that 

 these plants were sold by M. Adam, as a variety of C. purpureus, 

 before they had flowered; and the account was published by 

 Poiteau after the plants had flowered, but before they had ex- 

 hibited their remarkable tendency to revert into the two parent 

 species. So that there was no conceivable motive for falsification, 

 and it is difficult to see how there could have been any error." If 

 we admit as true M. Adam's account, we must admit the extra- 

 ordinary fact that two distinct species can unite by their cellular 

 tissue, and subsequently produce a plant bearing leaves and sterile 

 flowers intermediate in character between the scion and stock, and 

 producing buds liable to reversion ; in short, resembling in every 

 important respect a hybrid formed in the ordinary way by seminal 

 reproduction. 



I will therefore give all the facts which. I have been able to 

 collect on the formation of hybrids between distinct species 

 or varieties, without the intervention of the sexual organs. For 

 if, as I am now convinced, this is possible, it is a most im- 

 portant fact, which will sooner or later change the views held 

 by physiologists with respect to sexual reproduction. A 

 sufficient body of facts will afterwards be adduced, showing 

 that the segregation or separation of the characters of the 

 two parent-forms by bud- variation, as in the case of Cytisus 

 adami, is not an unusual though a striking phenomenon. 

 We shall further see that a whole bud may thus revert, or 

 only half, or some smaller segment. 



The famous bizzarria Orange offers a strictly parallel case to that 

 of Cytisus wlami. The gardener who in 1644 in Florence raised 

 this tree, declared that it was a seedling which had been grafted ; 

 and after the graft had perished, the stock sprouted and produced 

 the bizzarria. Gallesio, who carefully examined several living 

 specimens and compared them with the description given by the 

 original describer, P. Nato, 100 states that the tree produces at the same 

 time leaves, flowers, and fruit identical with the bitter orange and 

 with the citron of Florence, and likewise compound fruit, with the 

 two kinds either blended together, both externally and internally, 



99 An account was given in the ' Gar- 

 dener's Chronicle ' (1857, pp. 382, 400) 

 of a common laburnum on which grafts 

 of C. purpureus had been inserted, and 

 which gradually assumed the charac- 

 ter of C. adami ; but I have little 

 doubt that C. adami had been sold to 

 the purchaser, who was not a botanist, 

 in the place of C. purpureus. I h<ive 



19 



ascertained that this occurred in 

 another instance. 



100 Gallesio, ' Gli Agrumi dei Giard. 

 Bot. Agrar. di. Firenze,' 1839, p. 11. 

 In his 'Traite du Citrus,' 1811, p. 

 146, he speaks as if the compound 

 fruit consisted in part of a lemon, but 

 this apparently was a mistake. 



