TABLE OF CONTENTS. xi 



cardinal veins. Eelations of caudal vein. The circulation of the yolk-sacTc. 



Previous observations. Various stages. Difference of type in amniotic Verte- 

 brates. The vascular glands. -Supra-renal and inter-renal bodies. Previous 

 investigations. The snpra-renal bodies. — Their structure in the adult. Their 

 development from the sympathetic ganglia. The inter-renal body. — Its struc- 

 ture in the adult. Its independence of supra-renal bodies. Its development. 



CHAPTER XII. 



THE ORGAXS OF EXCRETION, pp. 249 — 287. 



Previous investigations. Excretory organs and genital ducts in adult. In 

 male. — Kidney and Wolffian body. Wolffian duct. Ureters. Cloaca. Seminal 

 bladders. Kudimentary oviduct. In female.— ■'Wol&.Sin dnct. Ureters. Cloaca. 

 — Segmental openings. Glandular tubuli of kidney. Malpighian bodies. Ac- 

 cessory Malpighian bodies. Eelations of to segmental tubes. Vasa efferentia. 

 Comparison of ScylHum with other Elasmobranchs. Development of segmental 

 tubes. Their junction with segmental duct. Their division into four segments. 

 Formation of Malpighian bodies. Connection between successive segments. 

 Morphological interest of. Development of Miillerian and Wolffian ducts. In 

 female — General account. Formation of oviduct as nearly solid cord. Hymen. 

 In male — Kudimentary Miillerian duct. — Comparison of development of Miil- 

 lerian duct in Birds and Elasmobranchs. Own researches. Urinal cloaca. For- 

 mation of Woljian body and kidney proper. — General account. Details of forma- 

 tion of ureters. Vasa efferentia. — Views of Semper and Spengel. Difficulties 

 of Semper's views. Unsatisfactory result of own researches. General homo- 

 logies. Kesume. Postscript. 



