254 



DR A. J. WHITING ON THE 



PAGE 



The Splenic Fulp {continued) — 



in the Rat, 2S6 



in the Mouse, 287 



in the Guinea-pig, 288 



in the Hedgehog, 288 



in Man 289 



Commentary, 293 



Summary 293 



PART II. 



On tjie Physiology of the Spleen and Blood Formation. 



Chapter V. 



Historical Epitome, 296 



Description of Leucocythremic Spleen, . . . . 298 



PAGE 



298 

 301 

 302 

 309 

 310 



On Artificial Anaemia in Dogs, 



Description of Spleens of three Anaemic Dogs, . 



Two Experiments on Anaemia in Dogs, 



Results of Experiments, 



Summary of Effects of Haemorrhage, 



On Artificial Anaemia in the Rabbit and Description of 



Spleen of Anaemic Rabbit, 310 



PART III. 



Methods— Bibliography — Description of Figures. 



Chapter VI. 



Methods, 311 



Bibliography, 314 



Description of Figures 316 



PAET I. 



On the Comparative Histology of the Spleen. 



Chapter I. 

 The Supporting Frameivork of the Spleen. 



The following general description of the capsule, trabeculse, and sheaths of the 

 splenic vessels is based on the examination of the spleen of the Kitten. 



Tlie Tunica serosa consists of a single layer of somewhat thick endothelial cells, 

 which is continuous with the peritoneal lining of the body cavity, and in addition of a 

 thin layer of very finely fibrillated connective tissue that lies immediately subjacent to 

 the endothelial layer. 



Tlie Tunica propria differs from a true capsule in that it blends along its whole 

 under surface with the splenic parenchyma, from which it cannot be detached without 

 tearing the splenic substance. 



It is composed of two layers, one consisting of ordinary connective tissue and the other 

 of muscular tissue. The more superficial layer is formed of interlacing bundles of white 

 fibrous tissue, between which are a few lymphoid cells, and of many strands of elastic 

 tissue, which, when stained with picrocarmine, appear as highly refractile yellow bands 

 or dots according as they are seen longitudinally or in transverse section. About mid- 

 way in the thickness of the tunica propria spindle-shaped muscle fibre cells begin to 

 appear. They increase in number until, at the inner fourth of the capsule, they form a 

 continuous layer principally directed transversely to the long axis of the spleen. Above 

 the circular muscular layer, as well as below it, there are a few longitudinally arranged 

 muscle fibre cells. 



From the circular muscular layer of the capsule the trabeculse spring as gently curved 

 bands, and are themselves composed of non-striped muscle. 



As the artery enters the spleen, along with the nerves, at the hilus, it receives a 



