THE mechanism by which the marine tube-dwelling worms of the phylum Pogonophora obtain their food has remained obscure since Ivanov1 established that they have no conventional gut. Ivanov concluded that they are filter feeders, utilizing external digestion, while Carlisle2 has suggested that particles are actively picked up by the tentacles of the unitentaculate forms. Jagersten3 first put forward the idea that they absorb organic substances directly from solution, and this report provides evidence in support of his hypothesis.