DISEASES OF THE URINARY ORGANS. 151 



ing the kidney may be specially named the cystic form of the echino- 

 coccus tapeworm of the dog, the cystic form of the unarmed or beef 

 tapeworm of man, the diving bladderworm the cystic form of the 

 marginate tapeworm of the dog, and the giant strongyle the largest of 

 the round worms. These give rise to general symptoms of kidney dis- 

 ease, but the true source of the trouble is only likely to be detected, if 

 the heads or hooklets of the tape-worm or the eggs of the round worm 

 are found on microscopic examination of the urine. 



TUMORS OF THE KIDNEY HYPERTROPHY ATROPHY. 



The kidney may be the seat of cancerous or simple tumors, and it 

 may be unnaturally enlarged or reduced in size, but though there may 

 be signs of urinary disorder the true nature of the disease is seldom 

 manifest until after death. The passing of blood and of large multi- 

 nucleated cells in the urine (to be detected under the microscope) may 

 betray the existence of an ulcerated cancer of the kidney. The pres- 

 ence of cancerous enlargement of (superficial) lymphatic glands may 

 further assist and confirm the decision. 



RETENTION OF URINE. 



Inability to pass urine may come from any one of three conditions: 

 1st, spasm of the neck of the bladder; 2d, paralysis of the body of 

 the bladder; 3d, obstruction of the channel of outlet by a stone (cal- 

 culus), (see Plate xi), or other obstacle. 



In spasm of the neck of the bladder the male animal may stand with 

 the tail slightly raised, and making rhythmical contractions of the 

 muscle beneath the anus (accderatio urincc) (see Plate ix, Fig. 2), but 

 without passing a drop of liquid. In the female the hind legs are ex- 

 tended and widely parted, and the back is arched as if to urinate, but 

 the effort is vain. If the oiled hand is introduced into the rectum or 

 vagina, in the early stages of the affection, the bladder may be felt 

 beneath partially filled, but not overdistended with liquid, and its nock 

 or mouth firm and rigid. In the more advanced stages of the affection 

 the organ is felt as a great, tense, elastic bag, extending forward into 

 the abdomen. In this condition the ovcrdistended musrulur coat of 

 the bladder had lost its power of contraction, so that true paralysis has 

 set in, the muscle closing the mouth of the sack alone retaining its 

 normal contractile power. 



In paralyttin of the body of the bladder attention is rarely drawn to 

 the urinary disorder until the bladder has been distended to full reple- 

 tion, and is almost ready to give way by rupture and to allow the escape 

 of the contained liquid into the abdomen. Overdistvntion is the most 

 common cause of the paralysis, yet it may occur from inflammation of 

 the muscular wall of the bladder, or even from injury to the terminal 

 part of the spinal marrow. In this last condition, however, the tail is 



