320 Nutrition and Selection. 



latent condition. On completely latent characters no 

 effect can be produced; we are dealing solely with half 

 and intermediate races. '*In other specimens, however, 

 this is obviously not the case," says Goebel, ''they retain 

 their normal form even when grown in rich soil ; the 

 high nutrition operates on the malformation, not as a 

 cause, but as a releasing factor."^ 



It is a familiar fact that many garden plants de- 

 teriorate if they are allowed to remain for a long time 

 in the same place. They exhaust the soil and must, 

 therefore, be moved from time to time. This is true, 

 for instance, of Pansies, Anemones,- Dahlias, Petunias,'^ 

 the crested forms of many ferns^ and so on. Morren 

 planted out a specimen of Saxifraga decipiens which 

 had hitherto borne normal flowers on stony ground, into 

 good garden soil. In this it grew very vigorously, formed 

 larger flowers than before, and manifested at first a 

 slight transformation of its stamens into petals which, 

 however, increased gradually during the course of the 

 summer until ultimately the flowers became entirely 

 double.'^ In Hedychinni coronariuni the structure of the 

 flowers is also shown to be dependent on nutrition.^ 

 Wild apples and medlars lose their thorns in a few years 

 if they are transplanted to gardens, '^ and Carlina acaulis 

 becomes the so-called Var. canlcscens, in rich soil, a fact 

 which has already been recorded by Wolff in his Theo- 



' K. GoEBEL, Or^anographie, I, p. 159. Various instances are also 

 given by Burkill, Journ. Linn. Soc. Bot., Vol. XXXI, 1895, pp. 2i8fif. 



■ Vilmorin-Andrieux, Les fleurs de pleine terre, p. 87. 



^HiLDEBRAND, Bcv. d. d. hot. Gcs., Vol. XIV, 1896, p. 327. 



*L6wE, cited by Goebel, loc. cit. 



''Bull. Acad. R. Bdg., Vol. XVII, Pt. T, p. 424. 



•^ Fr. Muller, Flora, 1889, Pt. Ill, pp. 34''^-352, PL 16. 



' De Canpolle, Physiblogie vcgctalc, II, p. 721. 



