GENERAL PHYSIOLOGY OF THE EPITHELIUMS. 203 



searches, which have been nearly all undertaken in Ger- 

 many, and have produced in some cases "such unlooked- 

 for results that we even feel a sort of hesitation in relating 

 them." l 



2. The communication of the lymphatic radicles with the 

 corpuscles of the connective tissue was first pointed out by 

 Virchow, who found, in a hypertrophied tongue, lacunae 

 unprovided with genuine walls (lymphatic capillaries), and 

 containing prolongations of plasmatic cells, also hypertrophied. 

 Leydig and Heidenhain have been the principal advocates 

 of this theory; and the latter, in order to explain the absorp- 

 tion which takes place at the point of the intestinal villosi- 

 ties, supposes the existence of a network of plasmatic cells, 

 communicating, on the one hand, with the prolongations of 

 the epithelial cells, and on the other with the central chyle- 

 ducts. Kolliker also embraced this opinion, having tested it 

 by experiments on the lymphatic vessels of the tail of a tad- 

 pole, and Recklinghausen's view nearly resembles that of 

 these two writers : according to him the origin of the lym- 

 phatic vessels is found in a system of tubes which he calls 

 plasmatic tubes, into some of which, situated in the cornea, he 

 made injections, and which he considers as special lacunas 

 of the connective tissue. Now, according to Kolliker, these 

 lacunas exactly correspond to those parts specially designated 

 by Virchow under the name of corpuscles of the connective 

 tissue or plasmatic cells; though Recklinghausen persists in 

 considering them as special lacuna) containing cellular ele- 

 ments having no prolongations (and for which he reserves 

 the name of corpuscles of the connective tissue). However 

 this may be, this view tends towards the latest opinion which 

 has been enounced in reference to the origin of the lymphatic 

 vessels. 



3. The communication with the lacunce of the connective 

 tissue belongs partly to Recklinghausen's theory, but it has 

 been chiefly upheld by His, Tomnisa, and Schweigger-Seidel. 

 According to His, there is direct communication between 

 the capillary vessel and the lacuna, on account of the disap- 

 pearance of the epithelium of the former : according to 

 Kolliker, the lymphatic capillaries are not intra-cellular but 

 inter-cellular tubes. 



This last opinion is the one which appears destined to tri- 



1 H. Beaunis, " Anatomie Generale et Physiologic du Systeme 

 Lymphatique." Strasbourg, These d'agregation, 1863. 



