686
R. H. THOMSON
Hamamelistes spinosus Shimer and H. betulae Mordvilko (238). Red,
water-soluble pigments, heteroaphins, are present in the hemolymph
(approximately 1% of the live-insect weight), which are converted by
enzymes (or acid) into a red, ether-soluble rhodoaphin, C30H22OH.
This can be reduced with zinc and acetic acid to an erythroaphin, and
it appears on present evidence, to be a hydroxylated erythroaphin.
4. Echinodermata
Quinone pigments make their only real contribution to animal coloring in this phylum. The varied hues of the spines and test (shell) of
many echinoids are due to the presence of polyhydroxynaphthoquinones.
A similar pigment occurs in at least one holothuroid, and polyhydroxyanthraquinones have been found recently in crinoids.
a. Echinoidea. A red pigment, "echinochrome," present in the coelomocytes of Paracentrotus lividus (Lam.) and Echinus esculentus Linn.,
was first described by MacMunn (240). The pigment was later isolated
from the eggs, ovaries, and other parts of Arbacia Uxula (Linn.) by
several workers and was named echinochrome A by Kuhn and Wallenfels (241), who determined its structure (CXLIII). Comparatively
large amounts of echinochrome A are present in the ovaries of this
species—as much as 10 mg. in a single ovary—but there is a seasonal
variation. Kuhn and Wallenfels (242) found that echinochrome A was
abundant in mature ovaries in March and April, but in the following
November and January the immature ovaries, which are small and deep
violet in color, contained relatively little echinochrome A but small
amounts of two new pigments, echinochromes B and C, had appeared.
Most of these latter had disappeared by the following March and much
echinochrome A was again present in the red-brown ovaries. Echinochrome B is a red compound, m.p. 173-175°, which appears to be
similar in properties to echinochrome A. Only very small amounts of
the violet echinochrome C were obtained. Spectroscopically it was similar to echinochromes A and B but could not be extracted from ether
with aqueous sodium hydroxide. Glaser and Lederer (243) also found
a high concentration of echinochrome A in the ripe ovaries of A. Uxula
but ripe testes contained none. On the other hand echinochrome A,
combined with protein, is present in the blood cells of both male and
female animals (244). Echinochrome-like pigments have been detected
spectroscopically in the organs of other species but are not invariably
present; e.g., two such compounds occur in the ectoderm, endoderm,
intestine, ovary, spermary, and egg cases of the purple sand dollar,
Dendraster excentricus, whereas D. laevis contains none (245, 246). A
similar pigment is present in the pale urchin Lytechinus pictus; the
R. H. THOMSON
Hamamelistes spinosus Shimer and H. betulae Mordvilko (238). Red,
water-soluble pigments, heteroaphins, are present in the hemolymph
(approximately 1% of the live-insect weight), which are converted by
enzymes (or acid) into a red, ether-soluble rhodoaphin, C30H22OH.
This can be reduced with zinc and acetic acid to an erythroaphin, and
it appears on present evidence, to be a hydroxylated erythroaphin.
4. Echinodermata
Quinone pigments make their only real contribution to animal coloring in this phylum. The varied hues of the spines and test (shell) of
many echinoids are due to the presence of polyhydroxynaphthoquinones.
A similar pigment occurs in at least one holothuroid, and polyhydroxyanthraquinones have been found recently in crinoids.
a. Echinoidea. A red pigment, "echinochrome," present in the coelomocytes of Paracentrotus lividus (Lam.) and Echinus esculentus Linn.,
was first described by MacMunn (240). The pigment was later isolated
from the eggs, ovaries, and other parts of Arbacia Uxula (Linn.) by
several workers and was named echinochrome A by Kuhn and Wallenfels (241), who determined its structure (CXLIII). Comparatively
large amounts of echinochrome A are present in the ovaries of this
species—as much as 10 mg. in a single ovary—but there is a seasonal
variation. Kuhn and Wallenfels (242) found that echinochrome A was
abundant in mature ovaries in March and April, but in the following
November and January the immature ovaries, which are small and deep
violet in color, contained relatively little echinochrome A but small
amounts of two new pigments, echinochromes B and C, had appeared.
Most of these latter had disappeared by the following March and much
echinochrome A was again present in the red-brown ovaries. Echinochrome B is a red compound, m.p. 173-175°, which appears to be
similar in properties to echinochrome A. Only very small amounts of
the violet echinochrome C were obtained. Spectroscopically it was similar to echinochromes A and B but could not be extracted from ether
with aqueous sodium hydroxide. Glaser and Lederer (243) also found
a high concentration of echinochrome A in the ripe ovaries of A. Uxula
but ripe testes contained none. On the other hand echinochrome A,
combined with protein, is present in the blood cells of both male and
female animals (244). Echinochrome-like pigments have been detected
spectroscopically in the organs of other species but are not invariably
present; e.g., two such compounds occur in the ectoderm, endoderm,
intestine, ovary, spermary, and egg cases of the purple sand dollar,
Dendraster excentricus, whereas D. laevis contains none (245, 246). A
similar pigment is present in the pale urchin Lytechinus pictus; the