FUNCTIONING OF THE SOIL SYSTEM - Soil Ecology - page 473

3.4 % tree leaves, and smaller proportions of roots (1.7 %), stems and other debris.
Comparison of the sizes and relative proportions of these dietary items indicates that
grasses and leaves are more completely digested than seeds, roots or stems.
Re-ingestion of casts is frequent in temperate climate anecic earthworms. It accounts
for 50 % of the diet of Nicodrilus velox , a large anecic of eastern France; the remaining
50 % comprises 20 % of leaf material and 30 % of mineral soil (Bouché et al., 1983).
This behaviour has also been noted in laboratory studies (Binet, 1993; Cortez and
Hameed, 1988) and clearly separates anecic from endogeic species since the latter do
not re-ingest their casts until their compact structure has been broken down.