314 



EPITHELIAL AND ENDOTHELIAL TISSUE. 



endothelia. These offshoots, up to the present time, were termed 

 "thorns of Max Schultze," in honor of their discoverer. This 

 observer, in 1864, described thorny or prickle cells in the epithelia 

 of the conjunctiva, the lips, the tongue of children, which, on 

 being isolated, exhibited rows of prickles, constituting the appear- 

 ance of "ridged cells." He knew that the prickles were conical 

 in shape, and in two adjoining epithelia so arranged as to resem- 

 ble two cog-wheels, the teeth of which are pressed into each 

 other, But expressed no positive opinion as to their significance. 

 Later observers, though their number was very great, did not 

 settle the question of the nature of the prickles. The only fact 

 admitted by all was that the prickles were very marked in epi- 

 thelia taken from localities which were subject to an irritation or 

 inflammation. Jin 1873, I declared the prickles to be formations 



FIG. 132. ENDOTHELIAL INVESTMENT OF THE PERITONEUM OF A 

 CHICKEN, SLIGHTLY STAINED WITH CHLORIDE OF GOLD. 



JE, polyhedral endothelia, separated from each other by light rims of cement-substance, 

 interconnected by delicate filaments; SS, stomata in the cement-substance; JBV, capillary 

 blood-vessel lined by endothelia, seen in edge-view; BC, blood-corpuscles. Magnified 600 

 diameters. 



of living matter, traversing the rims of the cement-substance and 

 interconnecting like bridges all epithelial and endothelial bodies 

 (see page 130). That the thorns are of universal occurrence in 

 the cement-substance and formations of living matter, can be 

 proved by different chemical re-agents and by the study of 

 pathological conditions, such as inflammation, fatty degenera- 

 tion, etc. In inflammation, and in certain tumors, an active new 

 growth of living matter starts from these filaments, which leads 



