Many, if not most, of our common forest trees bear 

 upon their roots certain peculiar fungi, the expanded 

 R F . growth of which is called "my- 



corhiza." These seem to have 

 highly specific and indispensable relations to the growth 

 and nutrition of their tree hosts. The subject is very 

 much in need of study; we know just enough about it 

 to indicate its great importance in all plans for reforesta- 

 tion and the maintenance of soil conditions favorable 

 to forest growth. Such large collections of the higher 

 fungi as are already in the Garden herbarium are an 

 essential part of the equipment necessary for the study 

 of these root-inhabiting forms. 



Tree production in nature is ordinarily a matter of 



decades and even centuries, hence greater rapidity of 



, „ , x . growth, combined with other good 

 Breeding and Selection ° . . . & 



qualities, deserves attention. The 

 already well established fact that hybridization is a 

 means of vastly accelerating growth is of fundamental 

 importance here. This is the subject of the researches 

 on the growing of pulp wood, in which a member of 

 the Garden staff is now acting as consulting expert. 

 The fact that many trees may be propagated by non- 

 sexual means, makes possible the immediate utilization 

 of rapidly growing hybrids as soon as they are secured, 

 without waiting for the establishment of varieties which 

 will come true to seed. Experiments in hybridizing 

 and selection for rapid growth should be extended to 

 all types of forest trees. The old problem of hybridizing 

 the conifers should be attacked from the standpoint of 

 modern methods. The peculiar forms obtained by 

 graft hybridizing should be further studied for the 

 light they may throw on our conceptions of plant or- 

 ganization and relationships. Further work is much 

 needed on the standardization of stocks for the propaga- 

 tion of fruit trees. 



En] 



