But even the most spiritual life has its temptations. The extravagant fever of industrialism and intellectualism had so subtly poisoned the plant-men that when at last they rebelled against it they swung too far, falling into the snare of a vegetal life as one-sided as the old animal life had been. Little by little they gave less and less energy and time to "animal" pursuits, until at last their nights as well as their days were spent wholly as trees, and the active, exploring, manipulating, animal intelligence died in them forever.
Source: tatoeba (8877818)