624 Validity of the Doctrine of Mutation. 



of an undonbted graft hybrid lias, however, as yet been 

 produced experimentally and, consequently, the charac- 



Fig. 140. Cytisiis Adami. A, A', bearing at I a bunch of 

 twigs of C. purpureus: P, H, and I. 



ters which such hybrids would have if they existed are 

 not known and can even hardly be guessed at. Therefore 



