669 



and by supplying aqueous vapor to prevent a too free radiation of the 

 earth's heat back into space at night. 



5 and 6. Distribution of Forests in North America ; their present and 

 prospective relation to the wants of man. 



7 and 8. Treeless regions of North America. How they limit areas of 

 cultivation by increasing areas of evaporation. How can the area of these 

 treeless regions be decreased, and at the same time made routes for con- 

 ducting water to areas of cultivation ? 



9. Necessity for such measures : Result — a true and legitimate economy 

 in government to aid in them. • 



10 and 11. Economic Arboriculture, as related to homes, home health 

 and the useful arts. 



12. Exotic trees to be introduced, and the proprietj^ of government sup- 

 porting extensive experimental and propagating arboretums. 



13 and 14. Plants of cultivation and the changes produced by cultivation 

 in them. 



15. How plants are constructed, i. e., popular sketch of their anatomy. 



16. How plants are perpetuated and how they "behave." 



17. Means taken to distribute them over the globe, and some striking 

 examples furnished. 



18. Succession of vegetable life on the globe. 



19. Chemistry of vegetation. 



20. Evidences of design in the vegetable kingdom. 



In the above I have endeavored to keep within the limitation implied in 

 the will of Andre Francois Michaux, i. e., that his legacy was intended to 

 contribute to the extension and progress of Agriculture and more especially 

 in Silvyculture in the United States. 



Very respectfully, J. T. ROTHROCK. 



M<iy 2, 1877. 



PROC. AMEK. PHILOf>. SOC. XVI. 99 4f 



