46 



RENAL AND REPRODUCTIVE ORGANS 



FIQ. 7. MALE ORGANS from the ventral surface. The right tcstis is turned over to show its efferent 



ducts 



Testes on the ventral side of kidneys. 



Vasa efferentia (L. afferent vessels), leading to inner side of kidney. 

 Kidneys in the dorsal part of abdominal cavity. 

 Duct passing from outer side of kidney to open into cloaca Genito-urinary canal, because 



it serves as ureter for the kidney and vas deferens for the testis. 

 FIG. 8. FEMALE ORGANS removed from body 



Ovary much folded and distended with ova. 



Oviduct distinct from ovary, anterior end opening beside gullet, posterior end in cloaca. 

 Ureter slender and opening into cloaca, posteriorly to oviduct. 

 Openings into cloaca Rectum. 



Urinary bladder, on ventral side of rectum independent of ureter. 

 Oviduct, anterior to opening of ureter. 

 Ureter. 

 FIGS. 9, 10. MALPIGHIAN CAPSULE OF HUMAN KIDNEY 



Tubule with its rounded dilatation, the Malpighian capsule. 



Glomer'ulus (L. a ball), the tuft of looped capillaries formed by afferent vessel from renal 

 artery, and uniting again to form an efferent vessel (vein), which breaks up into capil- 

 laries on the wall of the tubule. 

 Epithelium of capsule, glomerulus, and tubule. 

 FIG. 11. MALPIGHIAN CAPSULE OF FROG'S KIDNEY 



Epithelium lining tubule, with cilia to expel the urine. 

 FIG. 12. OVUM AND SPERMATOZOON OF COMMON FROG 

 Spermatozoon with vibratile tail. 



Tadpole or Larval Frog at different Stages. 



FIGS. 13, 14. EXTERNAL BRANCHIAE, three on each side of neck. 



Suckers, dilatations of the integument secreting a sticky substance. 

 Horny jaws. 



Operculum or gill-cover beginning to form. 

 FIG. 15. OPERCULUM grown over gills, leaving only a small opening on left side for some time. 



Hind-limbs appearing at first as tubercles, fore-limbs hidden by operculum. 

 FIG. 16. HEAD OF VERY YOUNG TADPOLE, magnified 

 Visceral clefts, six on each side of neck. 

 External branchiae, two on each side of neck (a third pair afterwards developed 



