312 CONCLUDING CHAPTER 
O. Lamarckiana in vigour and prolific habit, and two 
of them actually became established side by side with 
the parent type without man’s assistance. 
It is unfortunate from the point of view of de Vries’ 
interpretation of this case that the behaviour of 
O. Lamarckiana should suggest in some respects, as 
Bateson has pointed out, the phenomena of hybridiza- 
tion. It must be observed in support of de Vries’ 
view that the species appears to exhibit the same 
phenomenon in other localities, and, further, that it 
has not been possible to make any suggestion as to the 
second species with which the pure Lamarckiana might 
be supposed to have been crossed. 
From one point of view, as de Vries has himself 
pointed out, mutation in (Enothera is clearly a 
phenomenon of hybrids, and this circumstance of 
itself introduces considerable complications into the 
story. 
We saw just now that there is every reason for the 
conviction that mutation takes place in the germ- 
cells, and not in the zygote after fertilization. Since 
the number of mutants given off under the most 
favourable circumstances did not exceed 3 per cent. 
of the total offspring, the enormous majority of mutated 
germ-cells (on de Vries’ view) must unite with germ- 
cells bearing the ordinary specific character. Conse- 
quently, the new types which appear will in most cases 
have originated in the form of a cross between a mutated 
germ-cell and an ordinary germ-cell. And since this 
is not the final limit to the possible complications of the 
case, we can easily recognise that the complete inter- 
