'l M r. S. Deldpiiie. Contribution to llie [Dec. 18, 



DESCRIPTION OF PLATE 1. 



Remains of Phatcolonua gigot. 



Fig*. 1, la. Anterior and posterior aspects of an imperfect upper incisor. 



Figs. 2, Za. Outer and oral aspects of a fragment of the right mandibular ramu*. 



HI. 1, m. 2, i. 3, m. 4, molars ; t, incisor. 

 All the figures three-quarters natural size. 



1I[. * Contribution to the Study of the Vertebrate Liver." By 

 SHKRIDAX DELEPINE, M.B. Edin. Communicated by T. 

 LAUDER BRUXTON, M.D., D.Sc., F.R.S. Received No- 

 vember 20, 1890. 



(Abstract.) 



Preliminary Remarks. The following observations were made at 

 the end of last year in the course of an investigation touching the 

 action of drugs on cellular structure carried out by Dr. Lauder Brunton 

 and myself, for the Royal Society. 



Arrangement of the Hepatic Columns in a Classical Liver Lobule. 

 The following arrangement is visible in a plane perpendicular to the 

 direction of the terminal vessels occupying the centre and the peri- 

 phery of such a lobule. The columns of cells extend radially round 

 the hepatic veins only in tho direction of the portal veins, that is, in 

 three, four, or five directions at most. In the intermediate region 

 the columns present a typical feathery arrangement. The line from 

 which the columns diverge will be called hereafter hepatic line of 

 divergence. A similar arrangement is found around the terminal 

 portal veins, giving rise to what 1 call portal lines of divergence. 



Towards the portal lines of divergence the columns of cells become 

 smaller in diameter, and join each other, becoming continuous with 

 narrow tubes lined with flat epithelium and having the character of 

 intermediate tubes. These narrow channels open into more distinct 

 terminal bile ducts. 



Arrangement of the Bile Canaliculi. The liver columns branch from 

 the portal lim-s of divergence towards the hepatic lines. This 

 branching is, however, generally obscured by lateral anastomoses, 

 but it becomes more evident when the bile canaliculi are distinct. 



Two sets of bile canaliculi may be recognised : 



1. The main canalicnli, occupying the axis of the columns of cells 

 and becoming comparatively wide in the portal zone ; it is the branch- 

 ing of these which renders that of the columns so evident in some 

 specimens. 



2. The lateral canaliculi, which pass between the cells forming the 

 walls of the main canaliculi. 



