During the last 100 years, our view of ethylene has progressed from it being an environmental factor with profound effects on plants to an endogenous plant hormone controlling growth, development and reproduction. The ethylene story began with the work of Neljubov, a Russian graduate student. Previous work had indicated the adverse effect of illuminating gas on trees, but Neljubov (1901) was the first to describe the triple growth response of etiolated pea seedlings: (1) reduced stature, (2) exaggerated hypocotyl hook and (3) inhibited root growth (see Figure 1), which was subsequently shown to be due to hydrocarbons such as ethylene in the illuminating gas. When the method of heating banana-ripening rooms was switched from coke ovens to electric arc furnaces, it was noted that the fruit did not ripen so effectively, and it was eventually realized that the production of ethylene and other hydrocarbons during the combustion of coke actually stimulated ripening of the fruit. Later, it was found that hydrocarbons emanating from the lacquer coating the ballast chokes of lighting equipment, when in use, could affect the growth of plants in controlled environment rooms (Wills & Patterson, 1970).