OCCURRENCE OF CAUSATIVE AGENTS. 159 



PYELONEPHRITIS. 



A distinction is to be made between an ascending and 

 a descending pyelonephritis. The first variety, by far the 

 more common, is associated with the presence of identi- 

 cally the same microorganisms as is cystitis, upon which it 

 is dependent, and of which it represents the final, incurable 

 stage. The microorganism most frequently associated is 

 the bacterium coli or aerogenes. The descending variety, 

 with infection from the kidney, is usually a pyemic process, 

 and is dependent upon the related microorganism. 



In ascending pyelonephritis the bacteria gain entrance 

 into the pelvis of the kidney as the result of retention of 

 urine. No longer disturbed by the discharge of urine, 

 the microorganisms that have caused the inflammation of 

 the bladder wander into the ureter and, multiplying therein, 

 they finally, by extension upward, invade the pelvis of the 

 kidney. 



Chronic occlusion of the ureter may be followed by a 

 pure pyelonephritis, without preceding cystitis, when the 

 exciting agents of inflammation are present in the circulat- 

 ing blood, are eliminated through the kidneys, and collect 

 in the stagnating urine in the pelvis of the kidney. 



The bacteriologic diagnosis is only possible during life 

 if operation be performed. 



Experiments on Animals. After ligation of the 

 ureter, pyelonephritis can be induced in rabbits by means 

 of coli-bacilli or of pyogenic cocci, both by injection of 

 these bacteria directly into the pelvis of the kidney or into 

 the ureter above the ligature, and by intravenous iniection. 



INFLAMMATIONS OF THE FEMALE GENITAL ORGANS. 



Vulvitis. Suppurative inflammation of the vagina is 

 caused by the exciting agents of suppuration ; diphtheric 

 inflammation, by the diphtheria-bacillus ; gonorrheal in- 

 flammation, by the gonococcus. 



Endometritis. Puerperal endometritis is always of bac- 

 terial origin (streptococci, staphylococci, coli-bacilli) ; of 

 the remaining varieties of endometritis the majority are to 

 be attributed to gonorrhea. 



Salpingitis and Oophoritis. Inflammation of the tubes 

 and ovaries usually represents an extension of the endo- 



