66 ANATOMY OF THE LYMPHATIC SYSTEM.- 



consist of young endothelial cells, but the endothelial cells so pro- 

 liferating arrange themselves into a cord, which stretches freely over 

 the surface. In the exudation we find a great number of cells, which, 

 on account of their size, their granulation, and their nucleus, are very 

 sharply distinguished from the small pale blood or lymph-corpuscles. 

 In consideration of what we have said above, it will, I think, not meet 

 any opposition if we consider those corpuscles, reminding one of 

 endothelial cells, which occur in the exudation, as the products of 

 the endothelium. Besides, there can be no mistake that also a 

 large number of cells which are to be found in the exudation, rather 

 smaller, more or less pale, originate by the division of the former, for 

 there may be observed on the warm stage amoeboid movements and 

 division in those larger cells furnished with constricted or double 

 nucleus. 



There are intermediate stages between the forms first cited and 

 that of acute peritonitis of more moderate degree, just as there is a 

 complete gradation between acute peritonitis of the severest degree 

 and of the mildest ; and this depends, as is known, upon the intensity 

 and extent of the irritation employed, upon the animal itself, and 

 upon circumstances which we cannot enter upon in detail in this 

 place, as they lie quite without the boundaries of this description. 

 What we wish to show is the variety which exists in respect of the 

 changes of the endothelium that occur when we have to do with 

 a very intense acute peritonitis, viz. intense hypersemia, abundant 

 emigration of colourless blood corpuscles, and abundant thin exu- 

 dation fluid ; or with slight acute peritonitis, viz. slight hypersernia, 

 generally limited to the omentum, peritoneum of the centrum tendi- 

 neuin and intestinal covering, and no marked emigration of colour- 

 less blood corpuscresT^ For in the latter case it may be observed that 

 a lively germination of the endothelial cells takes place, limited 

 chiefly to those places where a germination could be made out 

 already under normal circumstances, namely, on the c : iJnin ten- 

 dineum around the stomata over the lymphatic capillaries of the 

 peritoneal surface, on the lymphangial knots and cords of the OIL antum 

 and of the mesentery, where we have met with pseudo-stomata and 

 true stomata in numbers, and, lastly, on the fenestrated parts of 



