ITS MORPHOLOGICAL CONSTITUENTS. 397 



themata, and at the commencement of every inflammatory irritation 

 of the kidneys. The second class of these cylinders consists of 

 fresh exudation, which is formed within the tubes of Bellini, 

 whose shape it retains, and consists of cylindrically granular parts, 

 inclosing blood-corpuscles and pus-corpuscles, and consisting 

 apparently of fibrin ; at all events they dissolve pretty readily in 

 alkalies, while the inclosed corpuscles are partly destroyed and 

 partly distributed in the fluid. As these are true croupous exu- 

 dations, they necessarily appear in all the inflammatory renal 

 affections which are usually included in the acute form of Bright's 

 disease. There is, however, frequently a third form of these 

 tubes, which occur in the shape of hollow cylinders witli walls, 

 which are so perfectly hyaline that they cannot easily be delected 

 under the microscope, unless by modifying the light. They are 

 frequently compressed together, or plaited as it were, and even in 

 some cases coiled round their axes. They generally occur only 

 scattered in the chronic forms of Bright's disease, as, for instance, 

 in fully developed fatty degeneration of the kidneys. When 

 treated with potash, they disappear, leaving only a fine, granular 

 substance. An epithelial cell, or a rudiment of it, may often be 

 observed in this species of cylinders, which I can scarcely regard 

 as anything but the membrana propria of the urinary ducts. 

 Acetic acid causes them to disappear, but I have been unable to 

 discover by washing with water, or by neutralisation with acids, 

 whether they have actually been dissolved, or have only swelled 

 up, and have thus attained the same refracting power as the sur- 

 rounding medium. They must not be confounded with the above 

 described croupous cylinders of fibrin. 



Spermatozoa are generally present in the urine after nocturnal 

 emissions, or the act of coition, and they are also believed to occur 

 in the somewhat rare affection of s'permatorrhoea. They are not 

 unfrequently found in the urine of typhous patients ; although in 

 these cases there may probably have been previous erection with 

 a discharge of semen, yet in this disease, they would sometimes 

 appear to have passed from the urethra into the bladder, since they 

 have been found attached to its mucous membrane in the bodies of 

 persons who have died of typhus. 



Elongated mucus-plugs, which appear, when examined under the 

 microscope, to consist of mucus-corpuscles arranged in rows, are fre- 

 quently met with after gonorrhoea, and the so-called youtte militaire. 



Blood-corpuscles aie of frequent occurrence; and, as maybe 

 conjectured, they may originate from very different sources. They 

 occur in small quantities in inflammations of the kidneys and 



