488 Drs. Herring and Simpson. Relation of the [May 31, 



Minot further believes that the supposed endothelial cells lining the liver 

 sinusoids do not form a true endothelium, but a layer of widely separated 

 mesenchymal cells, and he states that the physiological processes that take 

 place between the blood of a sinusoid and its adjacent parenchyma occur under 

 conditions very different from those where the blood flows in true capillaries. 



Ebner, in the last edition of Kolliker's " Gewebelehre " (Bd. 3, S. 664, 

 1902), admits that the embryonic liver contains wide capillaries, but does not 

 think that the fully-formed liver agrees with Minot's description, and regards 

 the employment of the term " sinusoid" as superfluous. 



In 1904 Lewis (39) emphasised the importance of Minot's discovery. 

 Lewis re-affirmed the particulars regarding the development of the liver given 

 by Minot, and states that the liver contains at first the smallest possible 

 amount of connective tissue, but that later an increase of connective tissue 

 •along the inferior vena cava transforms certain sinusoids into veins, while 

 another and more extensive growth along the bile ducts and portal veins 

 takes place, but never spreads into the lobules. Sinusoids persist between the 

 hepatic columns throughout life, and the so-called central veins of the lobules 

 are large vessels which replace several smaller ones, and in structure remain 

 sinusoids rather than veins. 



All who have worked at the subject are agreed that the blood-vessels inside 

 the liver lobules present special features. There is a unanimity of opinion 

 that very little connective tissue exists between their walls and the adjacent 

 liver cells. Most recent observers agree that there is a scaffolding of fine 

 -connective-tissue fibres which can only be seen after the employment of 

 special stains. The connective-tissue cells described by earlier authors have 

 been identified as Kupffer's cells, and shown to possess special phagocytic 

 properties ; they have been proved, moreover, by Kupffer himself, by Mayer, 

 Browicz, and Minot to enter into the formation of the walls of the blood- 

 vessels. Banvier and Kupffer believed that the walls are composed of a 

 syncytium with nuclei at intervals and accumulations of protoplasm around 

 them, varying in amount in different places. Browicz described cells actually 

 projecting into the blood-vessels. 



Hering could find no space between the cells lining the blood-vessels and 

 the liver parenchyma. Kupffer latterly, Browicz, Scbafer, and Minot have 

 insisted on the same thing. On the other hand, MacGillavry and many sub- 

 sequent observers claim to have injected perivascular lymph spaces, and 

 Kisselew and Beinke describe lymph spaces lined by endothelial cells. 

 Hering believes such injections to be artefacts, and Kupffer states that they 

 might be due to the injection lifting off an adventitial layer from the 

 capillary tube. 



