Rosa (roses), Salix (willows), and Quercus (oaks). Successful 
crosses between members of different genera belonging to the 
same family are not as numerous as between members of the 
same genus, although there are a sufficient number recorded to 
show there is a chance of securing them among genera that have 
not been tried out. Crosses between orchid genera are compara- 
tively common, this family having been the subject of very exten- 
sive commercial crossing, as practically every new form has a 
commercial value. Crosses between two different families are 
extremely rare. The only one of which I am aware is a cross 
between Digitalis atnbigua ( Scrophulariaceae ) and Sin?iingia 
speciosa ( Gesneraceae ). In general, then, the beginner should 
cross plants belonging to the same genus, unless prepared to do 
a lot of work for very few results, though these few results 
might prove to be of a very startling nature. 
Orland E. White. 
