272 SEROUS MEMBRANES, BY E. KLEIN. 



attains its greatest development at the posterior part of the 

 centrum tendineum. 



In addition to these statements made by Ludwig and 

 Schweigger-Seidel, it may be observed that in the Rabbit, Man, 

 and Cat, but especially in the Guinea-pig, a rich system of 

 serous canals and lymphatic lacunse, lined with endothelium, 

 can be demonstrated in the matrix itself, both on the abdominal 

 and thoracic surfaces, by treatment with nitrate of silver. On 

 the abdominal surface of the centrum tendineum of the Guinea- 

 pig we find that, from the trabeculse of the matrix containing 

 bloodvessels and nerves, smaller trabeculse, corresponding to the 

 divisions of the bloodvessels, are given oif tolerably rectilinearly, 

 separated by large wide fissures lined with epithelium. (See 

 vol. i., fig. 58, p. 317.) 



These lymphatic cavities receive on all sides the short lacu- 

 niform serous canals, as well as the longer and narrower vessels 

 that run in the larger trabeculse with bloodvessels and nerves, 

 and that are also in fact developed in the adventitia of the 

 former, and in the wide connective-tissue sheaths of the latter. 



These very wide lymphatic spaces communicate with the 

 fissures lined with epithelium, situated between the several 

 layers of the tendinous tissue. 



In the mesentery the larger lymphatics provided with valves 

 are situated in the principal trabeculse that pursue a radial 

 course from the root towards the intestinal border of the mem- 

 brane, and receive from all sides both small and large capillary 

 lymphatics, which, in the mesentery of the Frog, sometimes 

 originate in rounded or oblong wide lymph spaces that are 

 lined with epithelium, and sometimes proceed from the serous 

 canals themselves. The wide lymph spaces take origin from 

 the rhombic, stellate, or lacuniform serous canals, and occupy 

 the interspaces of the smaller trabeculse of connective tissue 

 that extend between the radially arranged chief trabeculse, and 

 intercommunicate by many smaller arched branches. 



In the mesentery of the Frog, as well as on the abdominal 

 surface of the centrum tendineum of the Guinea-pig, bloodves- 

 sels and nerves can here and there be distinctly seen imbedded 

 in lymphatic cavities, whilst in other parts they are accom- 

 panied on both sides by capillary lymphatics. 



