Transformation of Species 241 
investigators to form entirely different opinions. Our ultimate aim 
is to find a solution of the problem as to the cause of the origin of 
species. Indeed such attempts are now being made: they are justi- 
fied by the fact that under cultivation new and permanent strains 
are produced; the fundamental importance of this was first grasped 
by Darwin. New points of view in regard to these lines of inquiry 
have been adopted by H. de Vries who has succeeded in obtaining 
from Oenothera Lamarckiana a number of constant “elementary” 
species. Even if it is demonstrated that he was simply dealing with 
the complex splitting up of a hybrid}, the facts adduced in no sense 
lose their very great value. 
We must look at the problem in its simplest form; we find it in 
every case where a new race differs essentially from the original type 
in a single character only; for example, in the colour of the flowers 
or in the petalody of the stamens (doubling of flowers). In this con- 
nection we must keep in view the fact that every visible character in 
a plant is the resultant of the cooperation of specific structure, with 
its various potentialities, and the influence of the environment. We 
know, that in a pure species all characters vary, that a blue-flowering 
Campanula or a red Sempervivum can be converted by experiment 
into white-flowering forms, that a transformation of stamens into 
petals may be caused by fungi or by the influence of changed con- 
ditions of nutrition, or that plants in dry and poor soil become 
dwarfed. But so far as the experiments justify a conclusion, it would 
appear that such alterations are not inherited by the offspring. 
Like all other variations they appear only so long as special con- 
ditions prevail in the surroundings. 
It has been shown that the case is quite different as regards the 
white-flowering, double or dwarf races, because these retain their 
characters when cultivated under practically identical conditions, 
and side by side with the blue, single-flowering or tall races. The 
problem may therefore be stated thus: how can a character, which 
appears in the one case only under the strictly limited conditions of 
the experiment, in other cases become apparent under the very much 
wider conditions of ordinary cultivation? Ifa character appears, in 
these circumstances, in the case of all individuals, we then speak of 
constant races. In such simple cases the essential point is not the 
creation of a new character but rather an alteration of this character 
in accordance with the environment. In the examples mentioned 
the modified character in the simple varieties (or a number of 
characters in elementary species) appears more or less suddenly and 
is constant in the above sense. The result is what de Vries has. 
1 Bateson, Reports to the Evolution Committee of the Royal Society, London, 1902; ef. 
also Lotsy, Vorlesungen, Vol. 1. p. 234. 
D. 16 
