Chap. XL FLOWERS. 359 



Hence, after having carefully compared numerous varieties, I gave up 

 the attempt as too difficult for any one except a professed botanist Most 

 of the varieties present such inconstant characters, that when grown in poor 

 soil, or when flowering out of their proper season, they produce differently 

 coloured and much smaller flowers. Cultivators speak of this or that kind 

 as being remarkably constant or true ; but by this they do not mean, as in 

 other cases, that the kind transmits its character by seed, but that the 

 individual plant does not change much under culture. The principle of 

 inheritance, however, does hold good to a certain extent even with the 

 fleeting varieties of the Heartease, for to gain good sorts it is indispensable 

 to sow the seed of good sorts. Nevertheless in every large seed-bed a few 

 almost wild seedlings often reappear through reversion. On comparing 

 the choicest varieties with the nearest allied wild forms, besides the 

 difference in the size, outline, and colour of the flowers, the leaves are 

 seen sometimes to differ in shape, as does the calyx occasionally in the 

 length and breadth of the sepals. The differences in the form of the 

 nectary more especially deserve notice ; because characters derived from 

 this organ have been much used in the discrimination of most of the species 

 of Viola. In a large number of flowers compared in 1842 I found that 

 in the greater number the nectary was straight; in others the extremity 

 was a little turned upwards, or downwards, or inwards, so as to be com- 

 pletely hooked ; in others, instead of being hooked, it was first turned 

 rectangularly downwards, and then backwards and upwards; in others 

 the extremity was considerably enlarged ; and lastly, in some the basal part 

 was depressed, becoming, as usual, laterally compressed towards the ex- 

 tremity. In a large number of flowers, on the other hand, examined by 

 me in 1856 from a nursery-garden in a different part of England, the 

 nectary hardly varied at all. Now M. Gay says that in certain districts, 

 especially in Auvergne, the nectary of the wild V. grandiflora varies in 

 the manner just described. Must we conclude from this that the cultivated 

 varieties first mentioned were all descended from V. grandiflora, and that 

 the second lot, though having the same general appearance, were descended 

 from V. tricolor, of which the nectary, according to M. Gay, is subject to little 

 variation? Or is it not more probable that both these wild forms would 

 be found under other conditions to vary in the same manner and degree, 

 thus showing that they ought not to be ranked as specifically distinct ? 



The Dahlia has been referred to by almost every author who has written 

 on the variation of plants, because it is believed that all the varieties are 

 descended from a single species, and because all have arisen since 1802 

 in Prance, and since 1804 in England. 188 Mr. Sabine remarks that " it 

 seems as if some period of cultivation had been required before the fixed 

 qualities of the native plant gave way and began to sport into those 

 changes which now so delight us." 189 The flowers have been greatly 

 modified in shape from a flat to a globular form. Anemone and ranun- 



Salisbury, in' Transact. Hort. Soc.,' 189 'Transact. Hort. Soc.,' vol. iii. 



vol. i. 1812, pp. 84, 92. A semi-double 1820, p. 225. 

 variety was produced in Madrid in 1790. 



VOL. I. 2 B 



