Antimicrobial defense of the earthworm

Discrimination of self and nonself is one of the features of all animal spe cies but the ways of elimination of nonself are different, Defense strategi es of invertebrates, which lack antibodies and lymphocytes, are based on in nate defense mechanisms. The study of such, undoubtedly less complex, defen se mechanisms in invertebrates ma) shed a new light on the more sophisticat ed immunity of vertebrates The main aim of this review is to show on one ex perimental model - an oligochaete annelid - cellular and humoral defense pa thways protecting against microbial infection.