“…Among such factors are: microbial toxins (Pier and Heddleston, 1970;Pier et al, 1971;Michael et al, 1973;Thaxton et al, 1974a), hypoxia (Tengerdy, 1970), heavy metals (Thaxton and Parkhurst, 1973;Morgan et al, 1975), non-ionic radiation (McRee et al, 1977), pesticides (Glick and Whatley, 1966;Glick, 1972Glick, , 1974Latimer and Siegel, 1974;Subba Rao and Glick, 1977a), mechanical stress (Schmidt et al, 1976), social interactions Gross and Siegel, 1965;Gross and Colmano, 1967, 1969Siegel and Latimer, 1975), restraint (Thaxton and Briggs, 1972), and nutrients (Tengerdy and Heinzerling, 1972;Tengerdy, 1976;Tengerdy and Brown, 1977).…”