GLANDS. 449 



300^800' Even where smallest, they are distinguished by their sharp 

 outline ; and the larger ones are conspicuous by their roundness and 

 transparency, for all above have predominantly fluid contents. 



" To explain this very remarkable phenomenon, I take leave to digress 

 for a moment from the straightforward pursuit of the inflammatory 

 changes. Any one who has made a dozen post-mortem examinations must 

 have observed cysts in the kidney ; and there can be few pathologists 

 who have not speculated on the origin of these growths. Their connection 

 with chronic obstructive diseases of the kidney being notorious, some ob- 

 servers have supposed them to originate in dilatation of the Malpighian 

 capsules ; while others have referred them to distention of the urinary 

 tubules. They exhibit great variety in size ; they are seen every day as 

 small as mustard seeds ; they have been seen as large as cocoa nuts. 

 Thus, they obviously range from a very conspicuous largeness to a size at 

 which the naked eye loses them. On microscopical examination of 

 cysted kidneys, the same uninterrupted gradation of size is seen to repeat 

 itself. The larger vesicles fill the field of the microscope ; the smaller 

 ones diminish progressively, so that scores of them may be in the field 

 at the same time. 



" A section of cysted kidney, carefully examined with a sufficient 

 magnifying power, may show an astonishing number of these minute 

 vesicles; a number quite disproportionate to that of the larger cysts 

 visible to the naked eye ; so that, sometimes, by a single one of the latter 

 class seen on the surface of the kidney, I have found myself guided to a 

 disease which is substantially a vesicular transformation of the ultimate 

 structure of the gland. The smallest cysts are simple nucleated cells, of 

 the same size (or rather within the same limits of size) as the common 

 secretory, or epithelial cells of the gland. From these cells they seem to 

 be distinguished by their very definite outlines, and by their transparent 

 fluid contents : but a step further in microscopical analysis shows that the 

 distinction ceases at this point. They show no signs of a specific origin ; 

 no germs can be found for them other than might equally belong to 

 epithelial development ; it seems as though from the same germs ac- 

 cording, no doubt, to varying influences healthy gland-cells might 

 grow, or these fluid-holding cysts. 



" Fuller investigation of the specimen reveals the following very sug- 

 gestive fact : the copious formation of cells occupies the place of tubes, 

 holding their relation to the vascular plexus of the gland ; and, as one 

 gets to the periphery of the portion of gland thus transfigured, one finds 

 the broken extremities of the original tubules, some empty and collapsed, 

 others obstructed and often dilated with morbid accumulation. In some 

 cases this obstructive material contains a large proportion of fat, or con- 

 sists of it almost entirely. 



" In short, in pursuing the minute anatomy of the cysted kidney, we 



o o 4 



