Journal of Agricultural Research voi. x 



Page 



Formation of "Black Alkali" (Sodium Carbonate) in Calcareous Soils 



Plate 62. A. — One-yeax-old lemon seedlings, showing the effect of additions 

 of lime and manure to the soil. B. — Two-and-one -half -month -old lemon 

 seedlings, showing the effect of alkali crust on ground. C. — Reservoirs, 

 showing the effect of a lime hardpan upon the formation of black alkali. . . 590 



Further Studies of the Mos.aic Disease of Tobacco 



Plate 63. Leaves of tobacco showing method of severing the midrib and 

 lateral veins in studying the distribution of the virus from the point of 

 inoculation. Leaf A, midrib severed at base. Leaf B, lateral veins on 

 both sides of midrib severed. Leaf C, lateral veins on one side of midrib 

 severed 632 



TEXT FIGURES 



Daily Variation of Water and Dry Matter in the Leaves of Corn and 



THE Sorghums 



Fig. I. Graphs showing the amoimt of water and dry matter in the leaves of 

 com, kafir, and milo for July 28 and 29, 1914, and the evaporation for 

 the corresponding period 16 



2 . Graphs showing the amount of water and dry matter in the leaves of 



com, kafir, and milo for August 3 and 4, 1914, and the evaporation 



for the corresponding period 17 



3 . Graphs showing the amount of water and dry matter in the leaves of 



com, kafir, and milo for August 10 and 11, 1914, and the evaporation 



for tlie corresponding period 18 



4. Graphs showing the amount of water and dry matter in the leaves of 



com, kafir, and milo for August 15 and 16, 1914, and the evaporation 



for the corresponding period 19 



5. Graphs showing the amount of water and dry matter in the leaves of 



com, kafir, and milo for August 25 and 26, 1914, and the evaporation 



for the corresponding period 20 



6. Graphs showing the amount of water and dry matter in the leaves of 



com, kafir, and milo for July 13 and August i, 1915, and the evapora- 

 tion for the same period 21 



7. Graphs showing the amotmt of water and dry matter in the leaves of 



com and milo for July 20 and 21, 1916, and the evaporation for the 

 corresponding period 22 



8. Graphs showing the amount of water in the leaves of com, kafir, and 



milo for July 26 and 27, 1916, and the evaporation for the correspond- 

 ing period 23 



9. Graphs showing the amount of water in the leaves of com and milo for 



August I and 2, 1916, and the evaporation for the corresponding 



period 24 



10. Graphs showing the amount of water in the leaves of corn, kafir, and 

 milo for August 10 and 11, 1916, with the evaporation for the corre- 

 sponding period 25 



A Further Contribution to the Study of Eriosoma pyricola, the 

 Woolly Pear Aphis 



Fig. I. Diagram showing the life cycle of Eriosoma pyricola 73 



