xv] Bud-sports 273 



under Domestication* in which Darwin collected the evi- 

 dence about the relation between peaches and nectarines. 

 The records proved abundantly, (i) that the seeds of 

 peaches may come up nectarines ; (2) that conversely the 

 seeds of nectarines may give rise to peaches ; (3) that 

 peach-trees may by bud-sports produce nectarines, the sport 

 either involving a part so large that a definite nectarine- 

 bearing branch is formed, or so small that only a segment 

 of a fruit is affected, part of the fruit being peach and part 

 nectarine ; (4) in one instance, the (Carclew) nectarine is 

 said to have produced a branch which bore peaches. 



With the exception of the last fact (4) the significance 

 of this series of observations is now clear. The nectarine 

 is essentially a glabrous variety of the peach, and on the 

 analogy of other cases, the hoariness of the peach is pre- 

 sumably a dominant character. Thus, when from the seeds 

 of peaches, nectarines spring, we perceive that this is the 

 ordinary phenomenon of a recessive variety arising from a 

 dominant hybrid. When, on the contrary, peaches are 

 produced from the seeds of nectarines, the fact plainly 

 suggests that the nectarine has been pollinated from a 

 peach. To come next to the cases of the bud-sports, that 

 in which nectarines appear on peaches must be interpreted 

 as meaning that in the formation of that bud or cell from 

 which the branch, or fruit, or part of a fruit, derived its 

 separate existence, the element or factor for the peach- 

 character was omitted. Therefore at some cell-division, 

 evidently a somatic division, segregation of the allelomorph 

 for hoariness must have taken place, and we are thus obliged 

 to admit that it is not solely the reduction-divisions which 

 have the power of effecting segregation. 



Case (4) remains unelucidated. The record is most 

 circumstantial, and its truth can scarcely be called in question. 

 Nevertheless it stands, so far as I know, as an isolated 

 instance. Whether the case is, as we might perhaps be 

 tempted to suppose, one of actual, de novo origin of a 

 dominant feature ; or whether, as seems more probable, 

 this particular tree was in reality a monstrosity due to 

 imperfect segregation of that character in the germ of a 



* Vol. i. p. 362. 

 B. H. 18 



