BY DR. KLEIN. 127 



liver, the organs arc cut away below the ligatures, so that the 

 diaphragm is covered only by the liver, the lumbar part of 

 the spinal column is then severed, and the division completed 

 by continuing the incision forwards on either side to the middle 

 line. Threads are then attached to the cut edges, by which, 

 the upper part of the body is suspended, head downwards, to 

 a ring of iron. The whole operation can be completed in from 

 three to five minutes. The next step is to pour the liquid to 

 be used (previously warmed) on to the diaphragm, in quantity 

 sufficient to cover it. For twenty or thirty minutes, artificial 

 respiration is maintained at regular intervals. The diaphragm 

 ma} 7 then be prepared as before for microscopical examination. 



The Cellular Elements of the Centrum Tendineum 

 in their relation to the Lymphatic System. The 

 pleural surface of the centrum tendineum of a rabbit, guinea- 

 pig, or any other small mammalian animal, is exposed as above 

 described, and carefully, but slightly, brushed with a camel- 

 hair pencil moistened with serum. Silver solution is then 

 poured over it, and, after a few minutes, water. Thereupon bits 

 are cut out for microscopical examination, which must be care- 

 fully separated from the parts in contact with their abdominal 

 surfaces. These must then be mounted in glycerin, with the 

 pleural side upwards. Immediately under the endotheliura 

 of the surface there exist large, flat cells, which are more or less 

 branched. In the neighborhood of the large vessels which pass 

 through the centrum tendineum these are so close together that 

 they are marked off from each other by mere lines of interstitial 

 substance, and appear as if they formed a second Ia3'er of flat 

 endothelial elements subjacent to the one brushed off. Under 

 these cells branched cavities are seen to exist, hollowed out in 

 a yellow or yellowish-brown ground-substance. When the 

 examination is made with sufficient care, it is found, first, that 

 each of these cavities contains a nucleated mass of protoplasm, 

 which completely occupies it ; and, secondly, that both the 

 cavities and their contents are in continuit}' with each other, 

 so as to form a network. This network of cavities was first 

 described by Recklinghausen, under the name of Saftcanaldifti. 

 We propose to call it lymphatic canaliculi, and the more or 

 less branched cells contained in them, lymphatic cells. 



If these are examined in a island of tissue surrounded by 

 lymphatic capillaries, it is seen that there are places in which 

 the cells are closer together and less branched than in others, 

 and that in such spots they are often arranged in linear series, 

 or in small groups, each cell being marked off from its neigh- 

 bors by interstitial lines, so that they resemble an endothelium. 

 This is particularly the case in the immediate neighborhood of 

 the lymphatic capillaries ; and here it can often be made out 

 that cells contained in canaliculi are in contact with the elc- 



