30 THE LIVER, BY EWALD HERING. 



Babbit, and other Mammals. According to a provisional communica- 

 tion by Kisselew,* these peri vascular lymphatic spaces in the liver 

 of the Dog and Pig possess an epithelium identical with that lining 

 the true lymphatics, and may consequently be regarded as perivascular 

 lymphatic vessels. All the observers just mentioned agree in stating 

 that these intralobular lymphatics freely communicate with the inter- 

 lobular lymphatics situated in the connective tissue of Glisson's 

 capsule. 



I am of opinion that the existence of such perivascular lymphatic 

 vessels has not hitherto been satisfactorily proved, although it is easy 

 to demonstrate perivascular spaces in the liver of Man and of the 

 Dog, and also, to some extent at least, to inject them. The cells in 

 both these cases, as has been already mentioned, easily separate from 

 the capillaries ; in preparations preserved in alcohol especially, in 

 which the capillaries as well as the cells shrivel, relatively wide 

 empty spaces appear between the two, which are obviously artificial 

 products. These spaces may be obtained of any width, according to 

 the mode of preparation, in the liver of Man ; the degree of shrivelling 

 undergone by the cells may also vary, according to the nature of the 

 antecedent disease, and the consequent constitution of the cells ; as, 

 for example, the amount of water they contain, and so forth. When, 

 as in the liver of Man and of the Dog, the connection between the 

 hepatic cells and the blood capillaries is only loose, a layer of fluid 

 may perhaps in some instances collect between the two, especially 

 in cases of vascular disturbance, by which the complete detachment 

 of the cells from the capillaries, as the hardening proceeds, is still 

 more favoured. All this, however, does not justify us in admitting 

 the existence of perivascular lymphatic vessels ; for on the same 

 ground it might be maintained that, since a certain quantity of fluid 

 exists between ' t the fasciculi of the fibrillar connective tissue, each 

 separate fasciculus is enclosed in a lymphatic vessel. The results of 

 injection are also inconclusive ; for the supposed perivascular lymphatic 

 vessels have only been injected by extravasation. But whither must 

 the injection pass, if it be driven with excessive force ? What is more 

 natural than that it should detach the easily separable hepatic cells 

 from the blood capillaries, and insinuate itself between them? In the 

 Kabbit their detachment does not occur, and hence no perivascular 

 lymphatics can be injected in the liver of this animal ; but we find that 

 here the injection constantly bursts into and fills the blood capillaries. 



* Centralblatt fur die medicinische Wissenschaften, 20th February, 1869. 



