A NOTE ON THE ABSORPTION SPECTRA OF THE BLOOD OF EUDISTYLIA GIGANTEA AND OF THE PIGMENT IN THE RED CORPUSCLES OF CUCUMARIA MINIATA AND MOLPADIA INTERMEDIA

¹ The Oceanographic Laboratories and the Department of Zoology and Physiology, University of Washington, Seattle

A spectrometric examination of the green pigment dissolved in the plasma of the tube worm, Eudistylia gigantea, and of the red pigment in the corpuscles of the sea cucumbers, Cucumaria miniata and Molpadia intermedia, has led to the following conclusions.

1. The green pigment of Eudistylia appears to be chlorocruorin. In the oxidized state it possesses an -band at 602-605 mµ and a -band at 554-555 mµ. In the reduced condition a main band occurs at 577-580 mµ with a second band suggested at 540 mµ.

2. The red pigment of Cucumaria appears to be erythrocruorin. In the oxidized state an -band at 580-581 mµ and a -band at 544-545 mµ are seen. When the pigment is reduced a band appears at 562-563 mµ as well as one at 530-532 mµ.

3. The red pigment of Molpadia, when oxidized, possesses a band at 611-615 mµ and another at 568-570 mµ. In the reduced condition a band at 588 mµ is evident. This spectrum does not agree with the spectrum of either chlorocruorin or of erythrocruorin. The new spectrum may indicate the existence of another pigment with the ability to combine reversibly with oxygen.