IV DEPARTMENT OF AGRICULTUEE BULLETINS 51-75. 



Department Bulletin No. 52. — The Anthracnose of the Mango in 

 Florida. Page. 



Introduction 1 



Source of infection 2 



Infection experiments 3 



Spraying experiments in the spring of 1912 4 



The experiment in the Flanders grove 4 



The experiment on the Hoop farm 6 



Spraying experiments in the winter and spring of 1913 - 7 



Discussion of the spraying experiments 8 



Influence of the weather on pollination 10 



Relations of weather conditions to the disease 11 



Summary 14 



Department Bulletin No. 53. — Object-lesson and Experimental Roads, 

 and Bridge Construction, 1912-13. 



Introduction 1 



Bituminous-concrete road 2 



Bituminous-macadam road 4 



Macadam roads 4 



Gravel roads -. 10 



Gravel-macadam road 14 



Brick-cinder road 15 



Sand-clay roads 15 



Sand-gumbo road 24 



Shell roads. , 25 



Earth roads.. ...^ ■..' ." 27 



Inspection of object-lesson roads 31 



Unfinished work 31 



Experimental roads, 1912-13 31 



Memphis-to-Bristol highway 33 



Bridge work, 1912-13 34 



Department Bulletin No. 54. — The Topographic Features of the Desert 

 Basins of the United States with Reference to the Possible Occur- 

 rence OF Potash. 



Introduction 1 



The Great Basin and its development 3 



The undrained areas of the United States 9 



The Lahontan Basin and its tributaries 11 



The Bonneville Basin and its tributaries 18 



The basins of the lava plateau 23 



The trough valleys of Nevada and the basins of the transition zone ... 31 



The trough valleys of Cahfomia and the Mojave Desert 38 



The Salton Basin 46 



The basins of the New Mexico-Texas trough 48 



The trough valleys of Arizona and Sonora 50 



The Lordsburg-membres region and the Chihuahua bolsons 51 



The Rocky Mountain basins 52 



The great valley of California 53 



The filled lakes of the CaUfomia ranges 54 



The basins and ponds of the Colorado Plateau 54 



The ponds and coulees of eastern \\'ashington 55 



The ponds of the Great Plains 56 



Local basins of unusual origin 57 



The possibilities of potash 58 



