Apr. 2-June 25,1917 
Illustrations 
VII 
Page 
Plate 29. A.—A pit slightly over 2 mm. in diameter, showing broken down 
cells, free starch, and fungal hyphae. B.—Fungal hyphae apparently pene¬ 
trating the cell walls. 426 
Plate 30. A.—The normal cortex and inner tissues of a potato tuber. B.—An 
enlarged lenticel, showing a very early stage of infection. C.—Fungal 
filaments and broken down cells in an infected lenticel slightly over 1 mm. 
in diameter. D.—A host cell highly magnified showing the interior filled 
with fungal hyphae. E.—The granular contents of one of the pits as it 
appears under the microscope. F.—Rhizoctonia hyphae from a pure culture 
isolated from the interior part of a dry core. 426 
TEXT FIGURES 
Wheat-Sheath Miner 
Fig. 1. Young wheat plant, showing (a) central stalk injured by the wheat- 
sheath miner, Cerodonta femoralis; ( b ) point where egg was laid; (c) 
mine in the leaf made by larva on its way to the sheath; other leaves 
normal. 20 
Relation of the Water-Retaining Capacity of a Soil to its Hygroscopic 
Coefficient 
Fig. 1. Diagram showing the relation of the percentage of water retained to the 
hygroscopic coefficient and the influence of an interrupting layer of 
coarse sand. 39 
2. Diagram showing relationship between the final water content and both 
the hygroscopic coefficient and the moisture equivalent.. 48 
3. Diagram showing the relative location of sets of soil samples taken from 
field near McCook, Nebr... 62 
4. Diagram showing relation of water content of the surface section to both 
the hygroscopic coefficient and the moisture equivalent five days after 
1 inch of water had been added to the surface of columns of dry soils.. 65 
Absorption of Nutrients as Affected by the Number of Roots Supplied 
with the Nutrient 
Fig. 1. Relation between portion of roots supplied with nitrogen and portion of 
maximum absorption attained. 89 
2. Possible relative rates of translocation of an element in plants with one- 
fourth and all their roots supplied with the element. 92 
Flow Through Submerged Rectangular Orifices with Modified Con¬ 
tractions 
Fig. 1. Standard box for submerged rectangular orifices with modified con¬ 
tractions . 98 
2. Plan, elevation, and section of orifice box in concrete channel... 100 
3. Elevation and sections of standard orifice without bottom contraction.. 100 
4. Elevation and sections of orifice with bottom contraction. 101 
5. Elevation and sections of orifice with iron gate guides. 101 
6. Elevation and sections of broad-edged orifice. 102 
7. Elevation and sections of broad-edged orifice with wood gate guides... 102 
8. Elevation and sections of broad-edged orifice with wood gate guides and 
wood backing. 103 
