Ohap. XI. aRAFT-IlVBUIDS. 417 



was cunseq\iently propagated. Now it deserves especial notice that 

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

 before they had flowered; and the accoi;nt was pxiblished by 

 Poiteau after the ])lants had flowered, but before they had ex- 

 hibited their remarkal)le tendency to revert into the two parent 

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

 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 subse(|uently 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 2'liysi*^^<^gists 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 Cijtisus 

 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 bizz irria Orauf/e offers a strictly i^arailel case to that 

 of C'i/fint(H wlaiiii. 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,'"" states that the tree i^roduces at the same 

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

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

 two kinds either blended together, both externally and internally, 



'^ An account was given in the ' Gar- ascertained that this occurred in 



deaer's Chronicle '(1857, pp. 382, 400) another instance, 

 ot'a common laburnum on which grafts '<"' Gallesio, ' Gli Agrumi dei Giard. 



of C. pwr/jMrcMS had been inserted, and Bot. Agrar. di. Firenze,' 1839, p. 11. 



which gradually assumed the charac- In his 'Traite du Citrus,' 1811, p. 



ter of C. adami; but I have little 146, he spealis as if the compound 



doubt that C. adami had been sold to fruit consisted in part of a lemon, but 



the purchaser, who vvas not a botanist, this apparently was a mistake, 

 in the place of C. purpureus. I have 



VOL. I. 2 E 



