XXII Journal of Agricultural Research voi. vi 



Effect of Climatic Factors on the Hydrocyanic-Acid Content of 



Sorghum 



Page 



Fig. I. Curves showing the hydrocyanic-acid content of sorghum on the various 



plots 264 



2. Curves showing the rate of growth of the sorghum on the various plots. . 265 



3. Curves showing the precipitation, temperatm-e, and humidity' relations 



at the various experiment stations during the growing season of 1915 . . 266 



4. Curves showing the contemporary climatic conditions at the various 



plots, together with crop data and hydrocyanic-acid content 267 



Hypodbrma deformans, an Undescribed Needle Fungus of the 

 Western Yellow Pine 



Fig. I. A side view of two apothecia of Hypoderma deformans on needles of 



Pinus ponderosa, showing the longitudinal medial split 278 



2. Asci, spores, and paraphyses of Hypoderma deformans 279 



3. Cross section of an apothecium of Hypoderma deformans on a needle of 



Pinus ponderosa, showing mature asci with spores, the point of first 

 rupture, and the tissues of the leaf most seriously affected by the 

 mycelium of the fungus 280 



4. The upper portion of a young ascus of Hypoderma deforynans, showing 



the formation of the pore at the tip through which the spores are 

 expelled 281 



CojiparativE Study of the Root Systems and Leaf Areas op Corn 

 and the Sorghums 



Fig. I. Evaporation from a free water surface (tank) at Garden Cit>% Kans., 



diuing the growing .seasons of 1914 and 1915 314 



2. Comparison of the leaf areas of Pride of Saline com. Black-hull kafir, 



and Dwarf milo at four stages of the growth of these plants diuing 



the season of 1914. 328 



3. A graphic illustration of the sheath areas of Pride of Saline com, Black- 



hull kafir, and Dwarf milo at four stages of the growth of these plajits 

 during the season of 1914 339 



Woolly Pear Aphis 



Fig. I. Comparative structure of antennae and wax pores of Eriosoma spp.: 

 A , distal segments of antenna of winged viviparous female of E. pyri- 

 cola; B, distal segments of antenna of winged viviparous female of 

 E. ulmi; C, distal segments of antenna of wingless viviparous female 

 of E. americanum; D, distal segments of an tenna of wingless vivip- 

 arous female of E. lanigerum; E, distal segments of antenna of 

 wingless viviparous female of E. pyricola; F, distal segments of 

 antenna of winged viviparous female of E. atnericanum; G, distal 

 segments of antenna of winged viviparous female of E. lanigerum; 

 H, compound wax pore of E. lanigerum; I, compound wax pore of 

 E. pyricola; J, distal segments of antenna of first instar wingless 

 viviparous female of E. pyricola 359 



Stimltlating Influence of Arsenic t;pon the Nitrogen-Fixing Organ- 

 isms op the Soil 



Fig. I. Graph showing the action of five compounds of arsenic on nitrogen 



fixation in dry soil 392 



2. Graph showing the effect of aeration on the nitrogen-fixing activit}'' 



of soil containing compounds of arsenic 408 



