Cytisus'Adami 223 



Of the last kind the Cytisus Adami serves as the most 

 beautiful and striking instance. It is a hybrid between 

 C. Laburnum and C. purptireits. Unfortunately its great 

 significance for the main features of the whole problem 

 has been underrated for a long time owing to the fable 

 of its having originated as a graft. As a matter of fact, 

 no hybrids are obtained by grafting, no matter how great 

 the mutual influence of the wild stock and the crown 

 graft. As far as historical evidence goes, the Cytisus 

 Adami has always been propagated by grafts since its first 

 appearance, but it did not originally spring into existence 

 in this way.^ 



This tree teaches us how the qualities of the two pa- 

 rents are combined. Ordinarily they occur mixed, the 

 leaves as well as the flowers having some features of the 

 Laburmim and others of the purpureas. The totality of 

 the characters lies, therefore midway between the two pa- 

 rents. But splittings do occur, and not at all rarely, or 

 rather so commonly, that indeed every specimen of the 

 hybrid, if not too small, will show them. In these split- 

 tings the types of father and mother separate sharply and 

 completely. Some twigs will grow. that are purely La- 

 hurnum, while others are only purpurciis. The former 

 are vigorous and long-lived, the latter remain weak and 

 often die after a few years, which is the reason for their 

 being seen less frequently. But even in this point they 

 resemble exactly the respective parents. 



Within the hybrid, the bearers of the parental charac- 

 ters are therefore arranged in such a manner that, so to 

 speak, they can be completely separated, at any moment, 



2Strasburger (Jahrb. Wiss. Bot. 42: 69-70. 1905.) finds entire 

 absence of an}' cytological evidence that C. Adami originated as a 

 graft-hybrid. Tr. 



