ALTERATION OF CELLULAR ELEMENTS OF MATRIX. 81 



of cells in inflammation. We have had already the opportunity to 

 mention the occurrence and the changes of vacuolated cells in the 

 normal oinentum. We have here only to add that in chronic inflam- 

 mation very numerous cells of the matrix of the serous membranes 

 become vacuolated, and change either into lymphatic vessels in the 

 way previously described, or they become elongated and join a capil- 

 lary blood-vessel. As regards the former case I had frequently occasion 

 to see that in some^of them a formation of lymphoid corpuscles takes 

 place from the wall of the vesicle into its cavity. Further, I have 

 met with large multi-nucleated cells (myeloplaxes), in which there 

 was to be seen the transformation of the central portion into a 

 number of lymphoid corpuscles, that of the peripheral part into the 

 nucleated wall of a vesicle endothelial vesicle. 



I refer the reader to Figures 18, 20, 23, 25, 27, 31, 33, and 53. 

 The most interesting fact as regards the vacuolation of cells I 

 have observed in the cells of the pseudo-stomata in chronic inflam- 

 mation. It occurs, namely, that in one of these a vacuolation takes 

 place, and the vacuole opens on one side free on the surface through 

 the process that stretches to the surface between the endothelium, 

 whereas towards the opposite side it becomes connected with a 

 lymphatic capillary, so that we have then before us the case that a 

 lymphatic capillary opens freely on the surface of the membrane by 

 a vertical canal, the entrance opening of which represents a true 

 storna. See Figures 27, 33A, 53, and 54. 



In Fig. 54, mesogastrium of a common frog, an endo-lymphangial 

 growth of a branched network is to be noticed in such an isolated 

 vacuolated cell, from which it can be inferred that endo-lymphangial 

 nodules develop in lymphatics in their earliest stage. 



3. The Blood- Vessels and Lymphatic Vessels. 



What has been said as regards the development of blood capil- 

 laries in the normal serous membranes is true also for chronic inflam- 

 mation, of course with greater extensity and intensity. 



Finally, we have to notice the intensive growth of a branched 

 reticulum from the endothelial wall into the lumen of lymphatic 



