450 THE SOLIDS. 



are conducted back to that same structural change which we found in 

 connection with sub-acute nephritis, and demonstrably dependent on 

 inflammatory processes ; or sometimes we are led to a change in some 

 respects similar to this, associated with what is known as the mottled 

 condition of the kidney. 



" The pathology of cysted kidiffey may accordingly be traced in either 

 of two directions ; from its first causation, or from its extreme pheno- 

 mena. Following the latter course, we have ascended to a period in the 

 history of cysts, in which they lie with numberless gland-germs amid the 

 remnants of broken tubules. The unbroken tubules around show no 

 growth of such cysts in their interior ; many are distended, it is true, 

 but not with^ cysts ; their distention is of a kind that we have already 

 investigated, inflammatory, or perhaps fatty. From the smallness at- 

 tained by the cysts, it seems quite obvious to me, that they cannot com- 

 mence in any transformation of the tubes themselves, or of the Malpighian 

 capsules. Accordingly, I find the same theory suggested by this method 

 of inquiry, as when the morbid change had been traced descensively 

 from its causes ; viz. that certain diseases of the kidney (whereof sub- 

 acute inflammation is by far the most frequent) tend to produce a 

 blocking up of the tubes ; that this obstruction, directly or indirectly, 

 produces rupture of the limitary membrane ; and that then, what should 

 have been the intra-tubular cell-growth continues with certain modifi- 

 cations as a parenchytic development. 



" During the growth of the cysts, they frequently exhibit an endo- 

 genous formation of cells which line them as an epithelium. 



" If I am right in my statement of facts, and if my theory of the cyst- 

 growth is sound, then the early stages of the process are certainly points 

 of great interest. For no one accustomed to the interpretation of nature, 

 can doubt the reparative tendency of these acts. The effused gland- 

 germs are the last phenomena of the original disease, and the first of the 

 attempted compensation. The transparent nucleated cysts, with their 

 clear sharp outlines, are not mere dropsical epithelia ; but are organised 

 for secretion into their own cavities, so as at least to withdraw from the 

 blood, if they cannot eliminate from the body, the materials which fill 

 them. 



" Returning now to the traces of inflammation in an uncontracted 

 kidney, we have yet to ascertain the condition of its blood vessels. 

 Numbers of the Malpighian bodies are extinct for all purposes of secre- 

 tion ; their vessels obliterated, their capsules wrinkled round them ; they 

 are dwindled, opaque, and bloodless. Sometimes the contraction of the 

 Malpighian bodies is secondary on that rupture of their capillaries which 

 Mr. Bowman has indicated as the source of intra-tubular haemorrhage ; 

 which rupture, of course, may have arisen either in an augmented im- 

 pulse of the arterial stream which fills them, or in an impeded circu- 

 lation through the venous plexus into which they discharge themselves. 

 But rupture of the capillaries is not the only cause of atrophy, to which 



