THE EARTH MOVED

An admirable portrait of that tireless ploughman: the earthworm.

In the detritusphere (the soil’s leaf litter layer) and below ground, the busy earthworm makes dirt and more, “folding the ruins of a city, a farm, or a society into the lower strata of the earth,” writes Stewart (From the Ground Up, 2001), who raises earthworms on her porch. She finds them endlessly fascinating, and they command her affection: “When I get home from a trip, the first thing I do is go outside and check on the worms.” As a gardener, she’s awed by the actions of these spineless wonders as they substantially alter the earth’s composition, increasing its capacity to absorb and hold water, bringing about an increase in nutrients and microorganisms. Stewart keeps the information digestible and poses all the questions we might have been afraid to ask. For instance, what are earthworms’ favorite human foods? Summer fruits, especially melon: “My worms eat a strictly vegan diet.” Stewart gives readers the benefit of her research, referring frequently to the copy of Darwin’s The Formation of Vegetable Mold, Through the Action of Worms she keeps close by her side and staying in touch with a hardy band of oligochaetologists who give her ideas to chew on, including the possible use of earthworms to process sewage and to reclaim polluted soil. The neatest trick in the earthworm’s bag is regeneration, its ability to grow replacements for amputated parts—even if it sometimes dooms itself by mistakenly growing a second head. Not that the earthworm is all beneficence, for just as it kills off harmful bacteria and fungus, it can also spread them, and worms can become detrimental to certain ecosystems, as when they were introduced to the forest understory and proceeded to displace local flora and fauna.

A nifty piece of natural history. Earthworms of the world can stand a little taller.