he had migrated to every corner of the planet and had left no meaningful trace of himself in any of the places hed visited save for his blood , his feces , his tears , his sweat , his seminal fluids , his dead skin cells , his hair , his nail clippings , and his countless other kinds of organic material ( naturally , in addition to these were the various pollens , spores , insects , fungi , rodents , birds , crustaceans , worms , planktons , and the millions of other unidentifiable microorganisms that had also migrated with him ) .