Back in the 1970s, plant pathologist W.Q. Loegering coined the term 'aegricorpus' to designate the 'new' organism created by the infection of a host by a pathogen (see his review 'Current concepts in inter-organismal genetics' in Annual Review of Phytopathology, 16: 309-320, 1976). This is what we would call a 'metagenome in today's terms, resulting in an 'extended phenotype' (sensu Dawkins, 1982). Should we thus regard Loegering as a pionner in metagenomics - and give him due credit for that -, or simply leave the 'aegricorpus' concept in its current oblivion?