1.46 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



0. leptocarpa flowers late, and has long, slender fruits which seldom 

 ripen; the stem is weak. 



0. nanella, as a dwarf, is weak, often incompletely developed; it 

 has a small quantity of pollen or none. The stigmas stick together. 

 The author says: These and other malformations of the dwarfs are 

 often due to a disease, and as such depend on outer circumstances "; 

 hence 0. nanella should be raised as a biennial, when it is stronger. 



0. scintillans is much more delicate than 0. Lamarcldana. 



0. elliptica is weak and very easily overgrown; it grew very slowly 

 even when transplanted and treated with every possible care. Many 

 rosettes died in the winter. Only ten plants flowered, but seed was 

 obtained from five; the pollen is often barren. This feature is " quite 

 normal for many species of Oenothera." 



0. suhlinearis is a weak species, mostly perishing as young rosettes; 

 only four survived, and one only had fertile seed. 



0. lata was solely female, so that its offspring were crosses, but 

 De Vries calls it a "species." The stem and branches are weak; 

 needing a support. It yielded very few seeds. 



The reader will see from the preceding that from a systematic 

 botanist's point of view scarcely one, if any, of these so-called species 

 are worthy of the name. One cannot escape from the conviction that 

 the features given as specific characters are simply individual varia- 

 tions due to a tendency to degeneration in consequence of being trans- 

 ferred from a xerophytic (sandy) environment to a soil supersaturated | 

 with manure. " Manure-sickness " would, therefore, be in all proba- j 

 bility the cause of their almost universal weakness, &c. j 



Having now given a brief account of the characters which Professor | 

 de Vries enumerates as characterizing his species " or " mutations," 

 his deductions must be considered. He often alludes to Jordan's 

 " elementary species " — i.e. the number of constant " forms " which, 

 collectively, make a Linnsean species. But, as to how they arise, his ; 

 view is that it is due to some internal causes, yet, apparently, not | 

 without some direct action of the conditions of life, as he accounted for 

 individual differences in the passage quoted above. Still he does not 

 appear to realize the obvious fact that in his own cultivations it was the 

 change from a barren " sandy soil " at Hilversum to a " heavily 

 manured " one at Amsterdam that gave rise to his, mostly, sickly race 

 of mutants. | 



Why he obtained several more or less definite results was, in his I 

 view, because Oenothera Lamarchiana happened to be passing through 

 a " mutation period "; that all his " species " were originally latent 

 in the parent form until he cultivated them, when they put in an ! 

 appearance. Here, therefore, he fails to apply his own interpretation, j 

 quoted above. For there is no reason to assume any such latency, since 

 the changes are simply due to the responsive power of the protoplasm, 

 that is called into action by changed conditions of life. 



If such a latency were a universal trait of life then, it might be 

 argued that all the fleshy maritime species were latent in the thin- 



