xxiv Journal of Agricultural Research voi. v 
Fig. 3. Experiment 28. Curve showing the quantity (in cubic centimeters) of 
AT/5 nitrogen in 100 c. c. of digestion fluid, equivalent to approxi¬ 
mately 5 gm. of meat or 30 gm. of skim milk... 697 
4. Experiment 32. Curve showing the quantity (in milligrams) of amino 
nitrogen in 10 c. c. of digestion fluid. 702 
5. Curve showing the rate of growth of cats on an immature-veal diet_ 706 
6. Curve showing the rate of growth of newly bom cats. 707 
Relation between the Properties op Hardness and Toughness op 
Road-Building Rock 
Fig. i. Curve showing the results of tests of about 3,000 samples of road¬ 
building rock. 905 
Apparatus for Measuring the Wear op Concrete Roads 
Fig. i. Details of instrument for measuring the wear of roads. 953 
Morphology and Biology op the Green Apple Aphis 
Fig. 1. Map showing the localities in the United States from which the Bureau 
of Entomology has actual records of the green apple aphis {Aphis 
pomi) . 958 
2. Diagram showing the overlapping generations of the green apple aphis.. 982 
3. Diagram showing curves for percentage of experiments on the green 
apple aphis in which the sexes appeared.<. 987 
4. Genealogical diagram showing the forms and generations developing 
from one stem mother of the green apple aphis. 990 
Relation op Stomatal Movement to Infection by Cercospora Beti- 
COLA 
Fig. 1. Stomatal pore widths on heart, mature, and old leaves and cotyledons 
of the sugar beet in the field, together with temperatures and relative 
humidities taken among the plants. 1018 
2. Stomatal pore widths on mature leaves kept under different relative 
humidities in a humidity box and free in the greenhouse. 1024 
3. Stomatal pore widths on mature leaves kept under different relative 
humidities in a humidity box and free in the greenhouse. 1025 
4. Stomatal pore widths on mature leaves kept under different relative 
humidities in a humidity box and free in the greenhouse. 1026 
5. Stomatal pore widths, on mature leaves kept under different relative 
humidities in a humidity box and free in the greenhouse. 1027 
6. Cercospora beticola: Conidia germinating on a sugar-beet leaf, but germ 
tubes not entering or being greatly attracted by closed stomata. 1035 
A Method op Correcting for Soil Heterogeneity in Variety Tests 
Fig. 1. Diagram illustrating the method of obtaining the u calculated” yield.. 1042 
2. Diagram showing the observed and corrected yield (in grams) of grain 
on each of Montgomery’s wheat plots in 1908-9. 1044 
3. Diagram showing the observed, corrected, and calculated yield (in 
grams) of Montgomery’s wheat plots in groups of four, taken from 
figure 2.. 1045 
4. Diagram showing the yield of oats (in bushels per acre) on the 1915 
variety-test field at Highmoor Farm (Monmouth, Me.). 1046 
