XVI LIST OF ILLUSTRATIONS 



FIGURE PAGE 



203. Semi-diagrammatic illustration of dividing small branch of pul- 

 monary artery of guinea-pig . ... 183 



204. The capillary network connecting an arteriole and venule of the 



omentum of a young rabbit . . . 185 



205. Capillary vessel of the frog's mesentery . . . 185 



206. Two sinusoidal vessels from the medulla of the human adrenal . 186 



207. Precapillary venule and arteriole . . 187 



208. Transection of an arteriole and venule .... 188 



209. Transection of the wall of the human vena cava . . . 189 



210. A 13 mm. human embryo . 192 



211. ' Vasof ormative ' cells from the mesentery of a rabbit seven days old 193 



212. The parietal layer of the pericardium of a child . . 196 



213. The endocardium . 197 



214. Radial sections of the mitral valve, from the heart of a man . . 198 

 215. Human heart, opened from the right to show the atrioventricular 



bundle of His . 199 

 216. Reconstruction of the sino ventricular system (bundle of His) of 



the calf's heart . 200 

 217. Oxalatcd plasma of human blood clotted with thrombin, showing 



fibrin needles ... ... 204 



218. From a freshly prepared, unstained specimen of human blood . 205 



219. Blood cells from a specimen of freshly drawn unstained human blood 206 



220. Showing the action of water upon the red blood corpuscle . . 206 



221. Five nucleated red cells (erythrocytes) from the blood of a frog . 207 

 222. Three nucleated red blood cells (erythrocytes) from the marrow of a 



human rib . ... 207 



223. A group of cells from normal human blood . . . 208 



224. A group of blood platelets, from the human blood . . . 209 

 225. Outline drawings of living polymorphonuclear leukocytes of rabbit, 

 from a drop of blood mixed with Ringer's solution to which a 



small amount of hirudin had been added to prevent coagulation . 211 

 226. Section of bone marrow from skull of 25 mm. turtle embryo (Chely- 



dra serpentina), showing three main stages in the hemopoiesis . 212 

 227. Hemoglobin crystals . . .213 

 228. Crystals of chlorid of hematin or hemin . . 213 

 229. Wall of yolk sac of a 13 mm. human embryo (Fig. 210), showing a 

 small blood island and several small blood-vessels contain- 

 ing erythrocytes . . .... 215 



230. Large blood island from yolk sac of a 13 mm. human embryo . 216 

 231. Diagrammatic illustrations of successive stages in the transforma- 

 tion of the mammalian erythrocyte to form the erythroplastid . 218 

 232. Successive stages in the elimination of the erythroblast nucleus, 



from homoplastic cultures of blood of a 32 mm. pig embryo . 218 



