One basic weakness in a conservation system based wholly on economic motives is that most members of the land community have no economic value. Yet these creatures are members of the biotic community. If its stability depends on its integrity, they are entitled to continuance. When one of these non-economic categories is threatened, and, if we happen to love it, we invent excuses to give it economic importance. At the beginning of century, songbirds were supposed to be disappearing. Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them. The evidence had to be economic in order to be valid. It is painful to read these roundabout accounts today. We have no land ethic yet, but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.