Origin of Wild Species 581 



with the discovery of a presumed mutation. In 

 many instances the authors have realized the 

 importance of this point, and new types have 

 been found constant from the very beginning. 

 Many cases are known which show no rever- 

 sions and even no partial reversions. This fact 

 throws a distinct light on our first point, as it 

 makes the hypothesis of a slow and gradual de- 

 velopment still more improbable. 



My third point is of quite another nature and 

 has not as yet been dealt with. But as it ap- 

 peals to me as the very soul of the problem, 

 it seems necessary to describe it in some detail. 

 It does not refer to the new type itself, nor to 

 any of its morphologic or hereditary attributes, 

 but directly concerns the presumed ancestors 

 themselves. 



The peloric toad-flax in my experiment was 

 seen to arise thrice from the same strain. Three 

 different individuals of my original race showed 

 a tendency to produce peloric mutations, and 

 they did so in a number of their seeds, exactly 

 as the mutations of the evening-primroses were 

 repeated nearly every year. Hence the infer- 

 ence, that whenever we find a novelty which is 

 really of very recent date, the parent-strain 

 which has produced it might still be in existence 

 on the same spot. In the case of shrubs or 

 perennials the very parents might yet be found. 



