Müller, 1833). During diastole, the posterior lymph hearts, however, on the actual rates of lymph flow. Earlier 1695The Journal of Experimental Biology 200, 1695–1702 (1997) Printed in Great Britain © The Company of Biologists Limited 1997

posterior lymph hearts are capable of generating flows that (approximately 80 %). Lymph heart flow and stroke volume returned to control values 30 min after addinglocated on either side of the urostyle, receive lymph from the surrounding spaces through numerous afferent pores. With each beat, these hearts eject lymph through a single efferent pore into the posterior vertebral vein (Radwanska, 1906, cited in Kampmeier, 1969). The importance of the anuran lymphatic system has been demonstrated numerous times by the inevitable death of animals 2–4 days after the destruction of their lymph hearts. These animals die from irreversible loss of plasma into the tissues because there is no appreciable return of lymph to the measurements of flow rates tended to be indirect and may be inaccurate. Using a visual estimation of stroke volume and by counting lymph heart rates, von Brücke in Winterstein’