THE BLOOD PIGMENTS OF URECHIS CAUPO

Abstract

The hemoglobin-containing red blood cells change during normal development of the individual from bright red through various intensities of brown to black, due to the gradual accumulation of hematin (identified spectroscopically). In [male][male] the hematin continually accumulates throughout life, being at the same time more and more converted to a black pigment; in the [female] the hematin markedly diminishes in the blood cells at sexual maturity and a black pigment coincidently appears in the protoplasm of the eggs. The black pigment of the eggs is probably derived from the hematin of the blood cells.