Oct. 1, 1919-Mar. IS. 1920 Illustrations xix 



Page 



Fig. 3. Diagram of plot B5-4, showing by the diagonal hatching the portions 



of the rows in which the cotton plants were killed by rootrot in 1918 . 307 



4. Diagram of plot B5-4, showing the portions of the rows in which the 



cotton plants were killed each year by rootrot in 1916, 1917, and 1918. 308 



5. Diagram of plot A4-19, showing the portions of the rows in which the 



cotton plants were killed each year by rootrot in 1916, 1917, and 1918. 308 



6. Diagram of plot A6-3, showing the portions of the rows in which the 



cotton plants were killed ea'h year by rootrot in 1916, 1917, and 1918. 309 



7. Diagram of plot B5-3, showing the portions of the rows in which the 



cotton plants were killed each year by rootrot in 1916, 1917, and 1918. 309 



Apple-Grain Aphis 



Fig. I. Effect of temperature upon the duration of the larval stages of the 



apple-grain aphis 318 



Relation of Moisti're in Solid Substrata to Physiological Salt Bal- 

 ance FOR Plants and to the Relative Plant- Producing Value op 

 Various Salt Proportions 



Fig. I. Diagrams showing the position of the cultures producing the nine 



highest yields of wheat tops in each series 364 



2. Average absolute yields of wheat tops for low, medium, and high 



moisture content of sand cultures 366 



3. Diagrams showing the position of the cultures producing the nine 



highest yields of wheat roots in each series 368 



4. Average absolute yields of wheat roots for low, medium, and high 



moisture content of sand cultures 370 



5. Amounts of water lost by transpiration from wheat plants grown in 



sand cultures with low, medium, and high moisture content 372 



6. Water requirement (in cubic centimeters per gram) of wheat tops grown 



in sand cultures with low, medium, and high moistiu-e content 374 



7. Water requirement (in cubic centimeters per gram) of wheat roots 



grown in sand cultures with low, medium, and high moisture content . 374 



Meat Scr.aps \'ersus Soybean Proteins as a vSt pplement to Corn for 



Growing Chicks 



Fig. I. Graph showing the rate of growth of males and females in all lots 392 



European Frit Fly in North America 



Fig. I. Map showing distribution of Oscinisfrit 454 



2. Egg of Oscinis frit 4c;e 



3 . Newly hatched larva of Oscinisfrit 4^5 



4. Full-grown larva of Oscinisfrit 456 



5. Oscinisfrit: Mouth hooks of ftill-grown larva 456 



6. Oscinis frit: Female abdou:en, distended with eggs and ovipositor pro- 



truded 457 



7. Oscinisfrit: Male genitalia, highly magnified 457 



Lepidoptera at Light Traps 



Fig. I. Light traps: A, opening for cone ; BBBB, plates of glass ; C, glass tube 



to convey acid; D, glass jar to hold cyanid; E, glass funnel 476 



