ON THE HEAD KIDNEY OF MYXINE. 359 



EXPLANATION OF PLATE 23, 



Illustrating Miss J. W. Kirkaldy's paper, "On the Head 

 Kidney of Myxine." 



b. c. Blood-corpuscles, b. m. Basement membrane. b. v. Blood-vessel. 

 c. Capsule, c. d. Central duct. c. n. Capillary network. e. to. Capillary 

 wall. f. Funnel, gl. Glomerulus outside the vascular wall. gl. d. Glome- 

 rulus of the central duct. /. Lumen of tubule, vi. Mucus, m. s. Anterior 

 end of mesonephron. n. Nucleus, p. c. Pericardial epithelium, p. t. Pro- 

 nephric tubule, s. Cilia, tc. d. Wall of central duct. w. v. Wall of vein. 



Fig. 1. — Head kidney of Myxine glutinosa. 



Fig. 2. — Diagrammatic longitudinal section. 



Fig. 3. — Transverse section through the head kidney to show the relations 

 of the central duct and the pronephric tubules. 



Fig. 4. — Transverse section, showing glomerulus. 



Fig. 5. — Glomerulus enlarged. 



Fig. 6. — Longitudinal section through a funnel, showing the columnar 

 animal, to show the central mass. 



Fig. 7. — Transverse section through the head kidney of a more mature 

 epithelium passing into the pericardial epithelium. 



Fig. 8. — Tubule from the same organ, with modified epithelial cells. 



