418 MANUAL OF HISTOLOGY. 



closing nucleated and nucleolated cells, mostly epithelial in 

 character. These cells generally line the interior of the vesicle 

 and nearly fill its cavity,' so that on section the vesicle looks 

 somewhat like an acinus of the pancreas. In the centre there 

 is often a branched nucleated corpuscle connected with a simi- 

 lar cell on one or the other side (Klein). The cells vary much 

 in size. In the connective tissue around the vesicles are lym. 

 phatic spaces and blood-vessels. 



The posterior lobe is smaller, darker, and more vascular 

 than the anterior. During foatal, and perhaps infant life, it 

 has a cavity in its interior lined with ciliated epithelium and 

 connected by the infundibulum with the third ventricle. 



Development. The pituitary body is formed by a diverticu- 

 lum from the future mouth (buccal epiblast), which projects 

 up to be transformed eventually into the anterior lobe ; and 

 another diverticulum from the wall of the vesicle of the third 

 ventricle, which projects down to form the posterior lobe 

 (Quain). Epiblastic and mesoblastic tissue are thus united in 

 the organ. The posterior lobe retains its nervous elements in 

 the lower animals, but in man contains little besides connective 

 tissue and blood-vessels. 



BIBLIOGRAPHY. 



THE SPLEEN. 



MflLLER, WM. Ueber den feineren Bau der Milz Leipzig und Heidelberg, 1865. 

 PEREMESCHKO. Beitrage zur Anatomic der Milz, und Ueber die Entwicklung der 



Milz. Sitzungsberichte der k. k. Akademie. Zu "Wien, 1867. 

 STRICKER, S. Manual of Histology. 1872. 

 QUAEN. Elements of Anatomy. New York, 1877. 

 BACELLI. Venous Circulation of the Spleen. Med. Times and Gaz., Vol. I., p. 532. 



1878. 



SAPPEY. Traite 1 d'anatomie descriptive. 3me ed. rev. et amel. 1879. 

 EANVIER, L. Traite technique d'histo'ogie. 1879 et seq. 

 KLEIN, E. Quarterly Jour. Mic. Science. No. LX., p. 363. 1875. Also, Atlas of 



Histology. Par. XIII. 1880. 

 FRET. Histology. 1880. 



THE PANCREAS. 



PFLCOER, E. P. W. Strieker's Manual of Histology. 1872. 

 BENAUT, J. Snr les organes lympho-glandulaires et le pancreas des vertebres. 



Compt. rend. Acad. des Sciences. VoL LXXXIX.. p. 247. Paris, 1879. 

 FOSTER, M. Physiology. 1880. 



