DISCONTINUOUS VARIATION 311 
imagining an asymmetrical nuclear division taking 
place immediately before the formation of the germ- 
cells, and this would lead us to expect a mutating 
species to give rise to more than one new kind of 
offspring at the same time. Such was actually the case 
with the Gnothera Lamarckiana studied by de Vries; 
and this observation stands as the most complete piece 
of evidence of a mutating species so far known to us. 
We may be assured, then, that the complete potential 
nature of new types as well as of old ones is already 
laid down in the germ-cells previous to fertilization. 
As Bateson puts it : ‘ For the first time in the history of 
evolutionary thought Mendel’s discovery enables us to 
form some picture of the process which results in 
genetic variation. It is simply the segregation of a 
new kind of gamete, bearing one or more characters 
distinct from those of the type. We can answer one 
of the oldest questions in philosophy. In terms of 
the ancient riddle, we may reply that the owl’s egg 
existed before the owl; or, if we hesitate about the 
owl, we may be sure about the bantam.’* 
Let us consider a little more closely the evidence of 
mutation afforded by de Vries’ studies of CEnothera 
Lamarckiana. Semi-wild specimens of this species, 
when transplanted and carefully observed, were found 
to yield nearly 3 per cent. of seedlings which differed 
definitely from their parent, and among these mutants 
some fifteen distinct new sorts were described. Some 
of the new species equalled or even surpassed the parent 
* British Association, Cambridge, 1904. Address to the 
Zoological Section, p. 14. 
