10 ANATOMY OF THE LYMPHATIC SYSTEM. 



exist such furrows; (2) that the surface of the serous membranes 

 is always moistened by a serous fluid, and consequently that fluid is 

 accumulated mostly in the above-mentioned furrows ; (3) that the 

 silver-salt produces precipitations in albuminous substances. If, 

 however, anyone concludes from these three circumstances the silver 

 lines correspond to precipitations in the serous fluid of the surface, 

 the conclusion is decidedly wrong, as the silver lines do not correspond 

 only and exclusively to these precipitations, for there exists a number 

 of facts which show that the existence of the silver lines depends also 

 and chiefly on precipitations in an intercellular albuminous substance, 

 which holds together the individual endothelial cells. The chief argu- 

 ment of Schweigger-Seidel, who first expressed the above-mentioned 

 erroneous opinion, and who defended it with great constancy, was, 

 that the appearance of the silver lines is prevented by rinsing the 

 surface of a serous membrane with diluted glycerine, or with diluted 

 sugar-solution. This assertion, however, I must contradict most 

 decidedly, as it is not the case either after rinsing with glycerine or 

 sugar-solution, nor even with water, provided that the membrane has 

 not been rinsed so much as to remove the endothelium altogether. Of 

 course, one can hardly expect that the silver lines should be of great 

 thickness in those instances in which the membrane has been rinsed, 

 as there exist no precipitations in a serous fluid of the surface which 

 would increase the precipitations in the intercellular substance. The 

 presence of various other lines on the surface of the silver-stained 

 membranes cannot be regarded from what has been said above by any 

 means as a proof against the silver lines being chiefly dependent on 

 the intercellular substance. We may mention here as well the very 

 regular system of silver lines corresponding to intercellular substances 

 in silver-stained sections of any mucous membrane covered with 

 laminated epithelium, e.g. cornea, conjunctiva, mucous membrane of 

 the mouth, sesophagus, larynx, vagina, &c., in silver-stained sections) 

 through masses of smooth muscular fibres, in the muscular coat of 

 silver-stained arteries, and so on. It remains, therefore, for the anta- 

 gonists of the intercellular lines only to deny the intercellular sub- 

 stance of the endothelium altogether, as it has been done by Robinski, 

 whose assertion it is scarcely necessary to discuss. 



