1914-15.] BOTANICAL SOCIETY OF EDINBURGH 341 



has recently passed through my hands, and I have come 

 to the opinion, after examination of it. that the species 

 ought not to be included in this section, and no mention of 

 it is therefore to be found in what precedes. 



In concluding my comments upon obconico-Lish ri at 

 the Conference, I said x : — 



" I have placed on view a series of photographs of forms 

 illustrating the variations rapidly sketched, and I offer 

 the problem involved in this complex section to students 

 of variation. 



"This variability in nature of the obconica type is from 

 the outlook of Botany a problem of some interest, because 

 in the thirty years during which the Ichang plant has 

 been in cultivation there has not been the varietal pro- 

 gression one would expect, even after allowing for the 

 handicap of its evil repute as an irritant : whilst P. sinensis, 

 Lindl., a plant also of the limestone rocks at Ichang, of 

 which in nature we have no record of variation — no wild 

 forms spread over an area outside its limited home on the 

 Yangtze — is in cultivation profuse, as we all know, in the 

 wonderful outshoots of vegetative and flower character it 

 makes. That there is a difference of constitution between 

 the plants growing side by side in native habitat must 

 have been recognised long ago by the Chinese, who have 

 made much of P. sinensis, Lindl.. but not of P. obconica. 

 Hance, and our experience in Europe confirms Chinese 

 empiricism. What we have to find out now is wherein is 

 the essential difference in the species. It is opportune 

 to present for investigation a case like this of two co- 

 habiting species, attractive as they grow in nature, of 

 cultural value, not distant in consanguinity, which outwardly 

 present equally valid characters of adaptation, yet the one 

 variable and consequently spreading in nature over a wide 

 area, but resistant in cultivation ; the other so little variable 

 in nature as to have a restricted boundary of distribution, 

 and yet in cultivation the parent of innumerable varieties 

 which are amongst the glories of horticultural skill. It is 

 no simple problem, the factors involved are many, but the 

 starting-point is admirably clear and definite in the two 

 wild plants growing together on the same range of rocks.'" 

 1 See Report of Primula Conference, 1913. p. 143. 



