The Sea Urchin

Early stages in the growth of the sea-urchin are presented in microphotography by transmitted and reflected light. Early stages in the growth of the sea-urchin are presented in microphotography by transmitted and reflected light. Early stages in the growth of the sea-urchin are presented in microphotography by transmitted and reflected light. Early stages in the growth of the sea-urchin are presented in microphotography by transmitted and reflected light.