9 



a little careful work. Numerous small ducts pass from the kidney 

 into the urinary duct. 



Open the uro-genital papilla near its tip and extend the incision 

 forward so as to open the sac connected with the base of the papilla. 

 The pore at the tip of the papilla leads into a space within the 

 papilla itself, the uro-genital sinus, which branches to the left and 

 right in pouches which extend beyond the posterior ends of the vasa 

 deferentia. These cornua of the uro-genital sinus are of variable 

 length, and are often named sperm-sacs. In a mature male they 

 may be found to be filled with sperm, as may also the seminal 

 vesicles and the convoluted portion of the Wolffian duct. The 

 openings of the vasa deferentia into the sinus are large and easily 

 located. The urinary duct opens into the sinus by a separate pore 

 just behind the opening of the vas deferens. 



Cut open the seminal vesicle and part of the convoluted vas 

 deferens. The space within is subdivided by transverse folds or 

 lamellae extending from a longitudinal ridge. 



No vasa efferentia can be distinguished in Eugaleus. The anterior extremi- 

 ties of the kidney and testis of each side come into close contact with each 

 other and here the vasa efferentia pass from the testis to the vas deferens. The 

 sperm-sac is a large blind pouch, one or two inches in length, leading out of 

 the posterior end of the vas deferens, and directed forward along its side. The 

 vas deferens of Eugaleus is not convoluted. 



In the young specimens usually supplied to laboratories the vas 

 deferens is straight and no seminal vesicle is developed. The vasa 

 efferentia are more difficult to see; otherwise the relations of the 

 urinary and genital organs are as in the adult. 



The suspensory ligament of the liver is continued posteriorly 

 along the midline of the ventral body-wall; the dorsal edge sup- 

 ports a funnel which opens into the abdominal cavity by a long, 

 narrow mouth. From the anterior end of the funnel two narrow 

 tubes pass to the right and left over the anterior surface of the 

 liver. They end blindly in the tissues dorsal to the anterior end of 

 the liver. These are vestiges of the Muellerian ducts (pronephric 

 ducts) which form the oviducts of the females. 



THE FEMALE. The ovaries are large, white bodies lying at the 

 sides of the stomach, dorsal to the lobes of the liver. Each is cov- 

 ered by the peritoneum and suspended by a fold of the same, the 

 mesovarium. Ova of various sizes may be felt in the tissue of the 

 ovary, which should be exposed by dissection. 



The ovaries of Eugaleus are long slender bodies lying on either side of 

 the mesogaster, dorsal to the stomach and intestine. Their posterior portions 

 are fused. 



The oviducts (Muellerian ducts) are large tubes suspended from 

 between the kidneys by a narrow peritoneal band. The posterior 

 portion of the oviduct, where development of the eggs takes place, 

 is considerably enlarged. Each oviduct opens separately into the 

 cloaca by a pore at the side of the urinary papilla. Followed for- 

 ward, the oviducts pass over the anterior surface of the liver and 

 following a continuation of the suspensory ligament, bend around 

 posteriorly and unite. At the point of union they open into the 

 coelom by a common, large, funnel-shaped aperture, the ostium 

 tubae. 



Cut through the peritoneum along the outer side of one kidney. 

 Then strip the peritoneum toward the inner side of the kidney. 

 Numerous small excretory ducts will be seen joining the main 

 urinary duct (Wolffian duct, mesonephric duct), which runs along 

 the inner margin of the kidney. Make an incision in the side of 



