390 LECTURE XVI. 



the convolutions of uriniferous tubules which have 

 mounted up to the surface. These yellowish, opaque- 

 looking convolutions correspond to fattily degenerated 

 uriniferous tubules, or to speak more accurately, to 

 uriniferous tubules filled with fattily degenerated epithe- 

 lium. If a section be compared with the surface, the 

 same markings are very distinctly seen to run through 

 the whole of the cortex, from the periphery down to the 

 upper borders of the medullary cones, and to invest the 

 individual cones formed by the tubuli recti which are 

 prolonged into the cortical substance at pretty regular 

 intervals. 



If sections are made in such a case in the neighbour- 

 hood of the surface and parallel to it, we readily obtain 

 a view embracing the fattily degenerated tubules by the 

 side of more normal ones, and of unaffected glomeruli. 

 With a lower power and by transmitted light, we see 

 close to the Malpighian bodies which appear as large, 

 light, globular structures, the convolutions of the de- 

 generated uriniferous tubules interlacing in various ways, 

 and the convoluted tubules distinguished by their opaque, 

 shaded appearance from the straight ones, which are 

 lighter and more translucent. 



I will here call your attention to the circumstance, 

 that in all fatty parts, where, by reflected light and as we 

 usually view objects with the naked eye, we see whitish, 

 yellowish, or brownish-yellow parts by transmitted 

 light, as generally employed for microscopes, and espe- 

 cially with the higher powers, either black, or brownish 

 black, or at least very dark parts, surrounded by 

 sharply-defined shadows, appear. A granule -globule 

 which, when lying together with several others, pro- 

 duces a spot white and opaque to the naked eye, will, 

 when viewed by transmitted light, display a nearly black 

 appearance. 



