Hæmoglobins, Myoglobins and Erythrocruorins: a Proposal for modifying the Present Terminology

Abstract

THE present terminology for those protohæm respiratory pigments which combine reversibly with oxygen, in which the terms hæmoglobin, myoglobin and erythrocruorin are used in varying senses by different authors, is far from satisfactory. Keilin and Hartree¹ showed that a convention introduced earlier by Svedberg², whereby all invertebrate pigments of this type were to be designated as erythrocruorins, was no longer justified on the basis of current knowledge. They suggested instead that ‘hæmoglobin’ should be used as a general term for both vertebrate and invertebrate pigments, and that the term erythrocruorin should be abandoned. According to their suggestion any given pigment should be identified by its origin, as in Planorbis hæmoglobin, muscle hæmoglobin, etc. It is with regard to the latter designation that this terminology immediately ran into difficulties.