28 On the Production of Hybrid Vegetables. 



quite satisfied that it is unsafe to rely upon the outward shape 

 of the ripe capsule as a generic distinction when its internal 

 structure and the form of the seeds agree. I have mules 

 from the long-podded Erica ampullacea and E. Jasminiflora 

 with the roimd-podded E. vestita-coccinea and E. hybrida 

 or cylindrica. I have also mules from E. Shannonia with 

 E. gemmifera and with E. tricolor, of E. ampuliacea with 

 E. gemmifera, and all the seedlings of a similar impregna- 

 tion are alike amongst themselves, and would at once be 

 pointed out, by a person acquainted with the African Heaths, 

 as new species extremely unlike their parents. These have not 

 yet flowered. I have not yet obtained any mule between tubu- 

 lar and campanulate flowering Heaths, but I have not made 

 many attempts. I think such difference of form much more 

 likely to constitute a true generic distinction in the family of 

 Heaths than that of a longer or rounder capsule. The un- 

 willingness of the African Heaths to shed their dust, unless 

 touched by a strong insect or humming bird, must render 

 them very likely to be fecundated by the dust of neighbour- 

 ing sorts : and if the hybrid offspring should prove fertile, 

 like that of the Gladioli, it will be evident how it comes to 

 pass that the species of x\frican Heaths are so multiplied, 

 whilst the European sorts continue unalterable. I am con- 

 firmed in this view by the information I have received, that 

 the different African species are very local, and not at all dif- 

 fused over the face of the country. 



Seeds, as it is well known, are originally existing in the 

 germen, and during the time of the expansion of the flower, 

 as the stigma advances to maturity, which often takes many 



