48 DISEASES OF THE KIDNEY. 



Schneider found worms in certain fish which seemed to represent 

 the early forms of a strongylus ; and the fact that the strongylus 

 species most generally infest fish-eating animals argues in favor of 

 this view. Its occurrence in man is very rare indeed. According 

 to Davaine, but seven well-authenticated cases have been collected. 

 We know, however, that in brutes the creature usually occupies the 

 pelvis of the kidney, more rarely descending the ureter into the 

 bladder, and that its presence causes symptoms similar to those of 

 calculus, and may cause retention of urine and hydronephrosis.] 



CHAPTER XII. 



DEFORMITIES OF THE KIDNEY IRREGULARITIES OF ITS SHAPE AND 



POSITION. 



ABSENCE of one kidney usually is accompanied by abnormal 

 magnitude of the other, and the secretion of urine remains normal. 

 Union of the two kidneys, which then are generally connected by a 

 narrow bridge of renal substance at their lower ends the so-called 

 horseshoe kidney is a matter of mere anatomical interest, and of no 

 clinical importance. The same is true also of lobulation of the kid- 

 ney, which depends upon a persistence after birth of 'the foetal con- 

 dition of the organ, and is distinguishable from an acquired lobular 

 state of the kidney by the healthy condition of the renal parenchy- 

 ma and capsule at the depressed points. Irregularity of position is 

 most common in cases of horseshoe kidney ; the united organs then 

 usually lie much deeper than natural, sometimes as low down as the 

 last lumbar vertebrae. But, even without the coexistence of this 

 malformation, an unnaturally deep position of the kidneys is not an 

 uncommon congenital deformity, and is usually accompanied by 

 irregularity in the origin and number of the renal vessels, as well as 

 by anomaly in the lengths of the ureters. 



Misplacement of the kidney, with abnormal mobility, is a mat- 

 ter of greater importance. Quite a considerable number of cases of 

 this anomaly have been observed since attention was first called to 

 it. In Greifswald alone I know of three cases of movable kidney. 

 The kidney (and almost always the right one) lies embedded in a 

 loose areolar tissue. Its vessels are elongated, and have a sort of 

 mesentery formed out of the reduplication of their peritoneal coat. 

 Such anomalies are most common among women whose abdominal 

 integuments have become greatly relaxed by repeated child-bearing. 

 According to Rayer, it may also result from violent concussion of 



