Evolution of host-parasite adaptation in nematodes of vertebrates

An analysis was attempted of the factors which determine the adaptation of Nematodes to their vertebrate hosts. A further analysis was carried out on the adaptation to the intermediate host or hosts. A distinction was made between the intermediate host harbouring pre-infective stages (L₁, L₂ and the beginning of L₃) and those harbouring post-infective larvae (the end of L₃ and L₄).