THE 



CYCLOPEDIA 



OF 



ANATOMY AND PHYSIOLOGY. 



EDITED BY 



KOBERT B. TODD, M.D. F.R.S. 



FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS; 



PHYSICIAN TO KING'S COLLEGE HOSPITAL; AND 



PROFESSOR OF PHYSIOLOGY AND OF GENERAL AND MORBID ANATOMY IN KING'S COLLEGE, 



LONDON, ETC. ETC. 



VOL. IV. 



P L A 



W R I 



LONDON: 



LONGMAN, BROWN, GREEN, AND LONGMANS. 



1852. 



