The comparison here implied between the actions of one of the higher animals and of one so low in the scale as an earth-worm, may appear far-fetched; for we thus attribute to the worm attention and some mental power, nevertheless I can see no reason to doubt the justice of the comparison.

Chapter 1: Habits of Worms, (p. 24-25) - The Formation of Vegetable Mould through the Action of Worms (1881)