618 



Validity of the Doctrine of Mutation. 



I shall not pursue this train of thought further ; l:>ut 

 this much seems to be clear, that germinal variations may 

 be the results of changes which have already taken place 



Fig. 137. Green Dahlia. A branch whose terminal inflores- 

 cence b as well as the lateral one b' have become green, 

 as in the remaining parts of the plant, whilst a branch 

 has arisen at a from an axillary bud, bearing double red 

 inflorescences of normal structure and without a trace of 

 virescence. a', flowering and a", a bud. See above, p. 

 92, Fig. 14 (1902). See also pp. 628-629. 



in the pollen- and egg-cells ; and that these changes them- 

 selves may have had their origin before the development 



