ON THE DEVELOPMENT OF THE CIRCULATORY SYSTEM OF THE YOUNG ASCIDIAN, CIONA ROBUSTA

Abstract

The studies concerning' the disposition of the blood vessels of ascidians have been presented by many investigators, but little has undertaken concerning developmental comparative anatomy of the circulatory system of the ascidian, It is interesting from the view point of comparative anatomy to know whether the circulatory system of the ascidian is comparable with the circulatory system of the vertebrates. To answer the question, the author previously studied the disposition of the blood vessels in the alimentary tract of an adult ascidian. This paper deals with the development of the circulatory system with concern about the alimentary tract of the ascidian.