THE BLOOD CELLS AND TUNIC OF THE ASCIDIANHALOCYNTHIA AURANTIUM(PALLAS). I. HEMATOLOGY, TUNIC MORPHOLOGY, AND PARTITION OF CELLS BETWEEN BLOOD AND TUNIC

Abstract

1. Then morphological blood cell types are recognized in Halocynthia aurantium. The mature morula cells, dispersed vesicular cells, stem cells, and stem cells with acidophilic vacuoles or granules decrease in differential distribution with increased weight of animal. The hyaline amoebocyte increases in differential distribution with increased weight of animal. 2. There is no significant difference in total blood cell concentration per cubic millimeter of blood as a function of weight of animal. 3. The mature morula cells, dispersed vesicular cells, hyaline amoebocytes, and granular amoebocytes are at significantly higher concentrations in the tunic of the body wall and stolon than they are in the blood. The mature morula cell is concentrated in the tunic just peripheral to the epidermis and the dispersed vesicular cell is concentrated at the external limits of the tunic. The hyaline amoebocyte is a phagocyte. 4. Upon injury to the tunic, the mature morula cells and dispersed vesicular cells increase significantly in the wound area over a 15 day period. The positional relationships of these cells are rapidly reinstated in the tunic. 5. The tunic consists of three components: epidermis, fibrous matrix, and cuticle with spines. The matrix consists of fibrous laminae which increase in number with increased weight of animal. 6. The mature morula cells, immature morula cells. compartment cells, and signet ring cells contain protein bound iron.