A Pale Hag-fish

Abstract

DE GRAAF¹ and more recently Ewer² have described specimens of Xenopus laevis lacking hæmoglobin. In the course of an investigation on the physiology of the heart of the cyclostome Myxine glutinosa, I found on August 20 an animal about 25 cm. long which was remarkably pale, except in the caudal and dorsal regions, which were grey. Its blood appeared to have no pigmentation due to hæmoglobin except near the gills, where there were some small localized red areas. All the blood vessels were cream in colour as well as the heart, although the ventricle might have been pink (? myoglobin, cytochromes). The liver was dark green and after fixation in 8 per cent formol the principal dorsal vessels showed a light greenish coloration due perhaps to the destruction of hæmin compounds. As for the gall bladder, it did not appear greener than normal.