In his news story "Is there a road ahead for cellulosic ethanol?" (Special section on Scaling up Alternative Energy, 13 August, p. 784), R. F. Service identifies factors contributing to fading enthusiasm for cellulosic ethanol and observes that policy-makers' decisions this year could shape the nascent U.S. biofuels industry for decades. It is critical at this time to distinguish the fundamental from the ephemeral and to base policy on the former rather than the latter. (Letters)