xxii LIST OF WOODCUTS. 



K IG- . PAGE 



216. Diagram of the Circulation of the Yolk-Sac at the eiid of the Third Day 



of Incubation in the Chick. (After Balfour. ) . . . 272 



217. Diagram of t;he Venous Circulation in the Chick at the Commencement of 



the Fifth Day. (After Balfour.) 273 



218. Diagram of the Venous Circulation in the Chick during the Later Days of 



Incubation. (After Balfour.) 274 



219. A, B, C. Diagrams of the Development of the Paired Venous System of 



Mammals (Man). (From Gegenbaur.) 275 



219. D. Diagram of the Chief Venous Trunks of Man. (From Gegenbaur.) . . 275 



220. Diagrammatic Section through the Human Gravid Uterus 276 



221. Diagram showing the Transformations of the Aortic Arches A, in a 



Lizard ; B, in a Snake ; C, in a Bird ; and D, in a Mammal. (After 

 Rathke.) (Seen from below. ) 277 



222. Hearts of Various Fishes A, of the Hammer-headed Shark (Zygoma 



malleus}; B, of Silurus glanis ; C, of a Selachian, cut open 278 



223. Diagram of the Arterial System of Fishes 279 



224. Diagram of the Heart and Branchial Vessels of Ceratodus. (Mainly after 



J. E. V. Boas.) 280 



225. Diagram of the Branchial Circulation of Protopterus 281 



226. Diagram showing the Course of the Blood through the Heart in Urodela 



(A) and Anura (B) 282 



227. The Arterial Arches of the Larva of a Salamander. (Slightly diagram- 



matic.) (After J. E. V. Boas.) 283 



228. Arterial Arches of an Adult Salamandra maculosa, shown spread out. 



(After J. E. V. Boas.) 284 



229. A, Heart of Lacerta muralis, and B, of a large Varanus, shown cut open ; 



C, Diagram of the Eeptilian Heart 285 



230A. Heart of the Swan, with the Right Ventricle cut open 286 



230s. Transverse Section through the Eight (Vd) and Left (Vg) Ventricle of 



Grus cincrea 286 



231. Five Different Modes of Origin of the Great Vessels from the Arch of the 



Aorta in Mammals 287 



232. The Arterial System of Salamandra maculosa 289 



233. The Arterial System of Emys europcea , 290 



234A. Diagram of the (Secondary) Connection of the Mesonephric Tubules with 



the Segmental Duct (Sg) 297 



234s. Horizontal Section through an Embryo of Lacerta agilis. (After M. 



Braun.) 297 



234c. The Entire Excretory System of the Embryo of Eylodes martinicensis 



(3 millimetres long). (After E. Selenka.) . 298 



235. Diagrammatic Transverse Sections of the Body of a Lower Vertebrate, to 



show the Relations of the Segmental Organs. (After Hensen.) The 

 right side of the figure represents a later stage than the left 299 



236. Diagram Exhibiting the Relations of the Female (A) and of the Male (C) 



Reproductive Organs to the General Plan (B) of these Organs in the 

 Higher Vertebrata 301 



