260 Genetic Interpretations in the Domain of Anatomy 



allowed ourselves to perpetuate. I mean the habit of applying the term 

 ligaments,, and the habit of applying the term fissures, to the liver ; also 

 the habit of describing the hepatic segment of the vena cava inferior as 

 a vessel distinct from the liver, it being in reality, strictly, in every sense 

 of the word, a portion of the organ. It may be further suggested that the 

 introduction of a new term, mesepatium, may assist in clarifying the 

 relations. The "mesepatium" is the membrane (French meso), which 

 stretches from the ventral border of the stomach and duodenum to the 

 median line of the ventral abdominal wall. It is in this membrane that 

 the liver develops. Above the liver, between it and the stomach, is the 

 dorsal mesepatium (lesser omentum). Between the liver and the body 

 wall is the ventral mesepatium (falciform or suspensory ligament). In- 

 stead of speaking of the ligaments, we should speak of the insertion of the 

 dorsal and ventral mesepatium into the liver ; and instead of coronary and 

 triangular ligaments, we should speak of the attachment of the liver to the 

 diaphragm. This area of attachment might be called, as regards the dia- 

 phragm, the hepatic area, as regards the liver, the phrenic area. 



With these preliminary explanations in mind, it may be suggested that 

 a description of the liver must begin, as many authors have begun it 

 already, with a general statement in regard to the position, size, color, 

 and general form of the organ, and explaining that it is a gland, with a 

 duct opening into the duodenum, and having the gall bladder appended 

 to it, and that the circulation is sinusoidal, and not capillary. 



Next, I should place a careful statement of the fundamental relations, 

 as follows, first, of the broad connection of the liver with the diaphragm. 

 This connection is primitive embryologically, is maintained throughout 

 life and constitutes the phrenic area. It is not by the so-called ligaments 

 or peritoneal folds, nor is it by the vena cava inferior that the liver is 

 attached ic the diaphragm. On the contrary it is by a large and charac- 

 teristically shaped phrenic area of the organ that the connection is 

 established. Second, the relation of the liver to the mesepatium, pointing 

 out especially that the insertions of the dorsal and ventral mesepatia 

 mark the division of the liver into right and left lobes and that the inser- 

 tion is enlarged at one point towards the right to form the so-called porta 

 of the liver, which admits from the dorsal mesepatium the hepatic artery, 

 bile duct, and portal vein. Third, the relation of the veins to the organ, 

 emphasizing that the portal vein marks the border of the dorsal mesepa- 

 tium, and that its branches within the organ mark the so-called portal 

 canals; emphasizing also that the umbilical vein or venous ligament 

 marks the free edge of the ventral mesepatium, and explains the position. 



