Organisms, general_______________________________________ Iron bacteria____________________________________________ Mechanics of iron concentration and depletion. ___________________ Lichen effects.__________-_-_________-__- .-___-_____-_-_-__ Hydrophyte (other than bacteria and fungi) effects. ___________ Chemical elements interfering with use of iron by plants_______-_-Measurement of materials affecting iron solubility _________________ Analytical ramifications of iron biochemistry._________________________ Selected references.-________________________________________________ Index.___________________________________________________________ in Page TABLE 1. Organisms that require iron for normal metabolism ____________ 133 2. Humic matter, dissolved oxygen, and tannic analyses-_________ 3. Methods of analysis for iron in water, soil, and plant material _ _ _