LYMPHATICS OF THE LIVER. 29 



it firmly in the hand for the short period that the injection 

 is entering, as this forms a sufficient obstruction to the escape 

 of the fluid ; no strong or persistent pressure must be applied 

 if it be desired to obtain trustworthy preparations. All other- 

 methods are far less satisfactory in their results. 



The illustrations of the lymphatics of the liver published by 

 Teichmann are so far imperfect that the various parts of the plexuses 

 are very unequally injected, and the vessels consequently everywhere 

 presented a knotted appearance. When well injected with a semi- 

 fluid injection, with moderate pressure, the lymphatics especially of 

 the capsule present remarkable regularity of form. 



Kolliker observed that in various animals the hepatic veins were 

 also surrounded by lymphatics, an arrangement which has not been 

 observed to occur in Man. According to Mac Gillavry, the deep 

 lymphatics of the liver of the Dog are in direct communication with 

 fissures in the connective tissue of the capsule of Glisson, that 

 possess no proper walls. This observer injected a watery so 

 gummy solution of Prussian blue against the valves in the large 

 lymphatics of the portal vein, or simply plunged the instrument into 

 the connective tissue. In either case considerable pressure was 

 required to propel the injection, both on account of the great extent 

 of the lymphatic system and the frequent occurrence of extravasations. 

 But since it is only by the detection of the characteristic epithelial 

 markings that it is possible to distinguish between a lymphatic vessel, 

 whose form has been altered by the employment of too great force in 

 driving the injection, and a fissure in the connective tissue caused by 

 extravasation, I do not myself, however, place much reliance on 

 Mac Gillavry's observations. And moreover the results of my 

 injections of the lymphatics of the liver in Man, performed as above 

 described, are opposed to his observations. 



According to Biesiadecki, the entire capillary system of the lobules 

 in Man floats in lymphatic spaces, the form and arrangement of which 

 are precisely similar to the capillaries themselves, except that they are 

 wider, and consequently contain the capillaries in their interior. On this 

 view the hepatic cells and the capillaries must everywhere be separated 

 by a space filled with lymph. These so-called perivascular lymphatic 

 spaces were originally described by Mac Gillavry* in the liver of the 

 Dog, and subsequently by Frey and Irmmgerf in the liver of the 



* Sitzungsberichte der Wiener Akademie der Wissenschaften, April, 1864. 

 t Zeitschrift fur wissenschaftliche Zoologie, 1860, Band xvi., p. 208. 



