54 ANATOMY OF THE LYMPHATIC SYSTEM. 



freely on the surface, between the endothelium, by perpendicular 

 canals. 



We shall show in the pathological part what great importance must 

 be ascribed to these freely-projecting cell-processes ; we call them 

 pseudo-stomata. A peculiar relation exists between these pseudo- 

 stomata and the young endothelium of the surface of those lymphatic 

 structures, which consists in the fact that the cell-process representing 

 the pseudo-stoma buds forth quite distinctly as a young cell. Of this 

 I have convinced myself in such structures, chiefly in the omentum of 

 the rabbit, but also in the omentum and pleura of the guinea-pig, 

 cat, and dog, both in surface aspects and also especially in profile 

 views. The nucleated buds, which, in form, size, and appearance, 

 are not to be distinguished from young endothelial cells, are seen to 

 project over the surface by a long thin peduncle. From the fre- 

 quency with which we see these bud-like young endothelial cells 

 sending a fine process vertically downwards between the surround- 

 ing young endothelial cells, we may conclude that a not incon- 

 siderable part of the young cells which bud forth from the surface of 

 a lymphangial nodule owe their origin to the pseudo-stomata. This 

 process, as we shall see, plays an important part in chronic inflam- 

 mation. 



(e.) Development of Lymphatic Cap^Uaries. 



We intend here to consider the development of lymphatic capillaries 

 only in so far as this takes place normally and to a relatively limited 

 extent in serous membranes ; in chronic inflammation we shall see 

 that this development takes place in a far greater degree. We shall 



only correct in so far as negative pictures are meant by it. There was consequently no 

 extreme necessity for Lavdovsky to claim priority for the discovery that the surface of 

 serous membranes possesses a number of minute openings, which communicate with the 

 lymph-canalicular system, since we contradict this statement when made with the mean- 

 ing he applies to it. Least of all can Lavdovsky claim priority for the perpendicular 

 lymphatic canals, of which we spoke on p. 19 of the preliminary communication of E. 

 Klein and Burdon-Sanderson, and to which Lavdovsky chiefly referred, as we have seen 

 that this is something radically different from his own views. What we designated per- 

 pendicular lymphatic canals were branches of lymphatic vessels lined by endothelium, 

 and opening freely on the surface. 



