268 SEROUS MEMBRANES, BY E. KLEIN. 



however, are accepted as stomata on the ground of the expe- 

 riments (10) of Recklinghausen, subsequently repeated by 

 Ludwig and Schweigger-Seidel, Dybkowsky, Schweigger- 

 Seidel and Dogiel, and Bohm. The successful injections of 

 Dybkowsky also tell strongly in favour of the existence of 

 stomata. (See fig. 8 in his treatise.) 



From an histological point of view, those small figures can 

 alone, strictly speaking, be regarded as stomata that occur in 

 the centre of radially arranged and relatively large endothelial 

 cells in such situations. With a little care we may find in most 

 cases, as Schweigger-Seidel and Dogiel (10) have pointed out 

 in the instance of the abdominal or external surface of the 

 wall of the cisterna lymphatica magna, that the nuclei of the 

 endothelial cells surround the supposed stoma, and lie close 

 around its periphery. All other small areas, whether isolated 

 or aggregated into groups of two or three, in all probability 

 only correspond to young cells proceeding from the fission of 

 larger ones. This view is supported first by the presence of 

 bi-nucleated cells, as in those of the mesentery of the Frog, 

 where the nuclei have undergone fission; secondly, by the 

 peculiarly irregular form of the endothelial cells in question, 

 which have precisely the appearance of having undergone 

 changes in form during life ; thirdly, by the circumstance above 

 alluded to, that here and there between individual larger 

 several small cells are introduced ; and lastly, by the discovery 

 of Ludwig and Schweigger-Seidel, that on the abdominal 

 surface of the centrum tendineum of the Kabbit all stages of 

 the division of the nuclei in the endothelial cells may be 

 witnessed. Ludwig and Schweigger-Seidel regard the cell 

 groups resulting from the division of the endothelial cells as 

 lymph corpuscles. 



I must still mention the cellular investment of the omentum 

 majus of the Cat. This consists of a very delicate framework 

 of connective tissue, with fissures that diminish in size towards 

 the larger fasciculi supporting the bloodvessels. 



The endothelium here closely invests the trabecular frame- 

 work. 



The methods already described of silvering and maceration 

 in iodine-serum are best adapted for its display. 



