322 THE LYMPHATIC SYSTEM, BY F. v . RECKLINGHAUSEN. 



tracted observation, to see a cell projecting from the terminal angular 

 extremity of one of these rootlets gradually become absorbed into it ; 

 and which, in its brightness, its refractile power, and its size, com- 

 pletely corresponded with those tissue cells which are in contact with 

 the lymphatic vessels ; as it was entirely absorbed, it was immediately 

 conducted, with moderate rapidity, but apparently passively, to one 

 of the main trunks. I have not as yet been able to observe one of 

 the stellate or fusiform connective tissue cells, which join with these 

 lymphatic vessels, or lie quite on their exterior, to be pushed onward 

 in a similar manner into the lumen of the vessel ; yet I regard it as 

 probable that this may sometimes occur. The above observation 

 renders it more than probable that the tissue cells are not strongly 

 adherent to the vascular wall, but lie in cavities which are continuous 

 with the lumina of the lymphatic vessels. Large granular cells may 

 also be seen in the interior of the larger- sized vessels of this descrip- 

 tion, lying near the wall, and at moderate distances from each other. 

 These are considered by Kolliker to be collections of fat molecules 

 constituting the remains of the primary formative cells ; they usually 

 present pale but well-defined outlines, possess numerous small teeth 

 and projections on their surface, some of which enter the cavity of the 

 vessel, whilst others penetrate the surrounding tissues. These cells 

 do not give. the impression that they are undergoing disintegration, 

 but rather appear to me to be simply the connective tissue cells 

 which hang from the interior of the larger vessels, and still remain 

 attached to their walls. It might, indeed, be considered that these 

 lymph passages or rootlets simply constitute expansions of the serous 

 canals, leading to others by means of their closely proximated pointed 

 processes, and an endeavour be thus made to prove that the serous 

 canals and lymph passages are continuous. The question may be asked, 

 do these persistent connective tissue cells under any circumstances de- 

 velop into epithelial cells ? I confess that I am unable to give a positive 

 answer, and shall only here remark that, like Kolliker, I have been 

 unable to obtain any evidence of the presence of an epithelial investment 

 in these vessels by the action of nitrate of silver. After being injected 

 with this fluid, the largest branches near the spine exhibited only con- 

 fused lines which might be regarded as indications of an epithelium, 

 whilst in the smaller vessels branched cells became coloured, around 

 which were a number of fine lines resembling coiled fibres. Whether, 

 as from this account appears probable, the peripherical portions of the 

 lymph canals are destitute of an epithelium, or whether such an 

 epithelium may yet be demonstrated by further investigations, all the 

 peculiarities of these vessels agree in a most remarkable way with the 



