GLANDS. 455 



attending symptoms are satisfactorily explained. My account of these 

 phenomena will be rendered more intelligible, if I give the facts and their 

 explanation at the same time. 



" On placing thin sections of the kidney under the microscope, some of 

 the tubes are seen to be in precisely the same condition as in a case of 

 acute desquamative nephritis ; they are filled and rendered opaque by 

 an accumulation within them of nucleated cells, differing in no essential 

 respect from the normal epithelium of the kidney : this increase in the 

 number, and this slight alteration in the character, of the epithelial cells, 

 are the result of the elimination by the kidney, of mal-assimilated pro- 

 ducts, which are being continually developed in these gouty and intem- 

 perate subjects, and which are not normal constituents of the renal 

 secretion. 



" There must evidently be a certain limit to the number of cells which 

 can be formed in any one of the urinary tubes ; for, although some of 

 the cells escape with the liquid part of the secretion, and so may be seen 

 in the urine, as in a case of acute desquamative nephritis, yet, in many 

 of the tubes, the cells become so closely packed, that the further forma- 

 tion of cells is impossible, and the process of cell-development, and, con- 

 sequently, of secretion within that tube, are arrested. The cells, thus 

 formed and filling up the tube, gradually decay and become more or less 

 disintegrated. While these changes are going on in the convoluted 

 portions of the tubes, the Malpighian bodies remain quite healthy, the 

 Malpighian capsules for the most part transparent, and the vessels in 

 their interior are perfect. From these vessels, water, with some albumen 

 and coagulable matter, is continually being poured into the tubes ; and, 

 as a consequence of this, the disintegrated epithelial cells are washed out 

 by the current of liquid flowing through the tubes, so that, on examining 

 the sedimentary portion of the urine, we find in it cylindrical moulds of 

 the urinary tubes, composed of epithelium in different degrees of dis- 

 integration, and rendered coherent by the fibrinous matter which coagu- 

 lates amongst its particles. The appearance of these casts are quite 

 characteristic of this form of ' chronic desquamative nephritis.' 



" There is reason to believe, that when the process of cell-development 

 and of secretion have once been arrested, by the tube becoming filled 

 with its accumulated contents, it never recovers its lining of normal 

 epithelial cells ; but, when the disintegrated epithelium has become washed 

 away from the interior of the tube, the basement membrane may be seen, 

 in some cases, entirely denuded of epithelium ; in other cases, a few 

 granular particles of the old decayed epithelium remain : and again, in 

 other instances, the interior of a tube, which has been deprived of its 

 proper glandular epithelium, is seen lined by small delicate transparent 

 cells, very similar to those which may sometimes be seen covering the 

 vessels of the Malpighian tuft. 



"It now becomes interesting to ascertain what further change the 

 tube undergoes, after having lost its normal epithelium. It is quite 



