514 Veterinary Medicine. 



The second form which may be called melanotic liver, is not 

 associated with atrophy, but is characterized by the crowding of 

 the hepatic cells with black pigment granules, which fill up the 

 protoplasm and crowd the still pale nucleus to one side. The 

 affected portions become of a deep black. 



In calves the pigmentation may be confined to the superficial 

 portion of the liver (Degive). 



In sheep pigmentation may be in the peripheral cells only of 

 the acinus (Cadeac) but is about equally distributed on the sur- 

 face, and throughout the interior of the liver, and may extend to 

 the stroma of the gland. (Siedamgrotzky). 



Apart from the general causes of melanosis, benignant or 

 malignant, no definite reason for this pigmentation has been 

 assigned. The development of melansemia and tissue pigmenta- 

 tion in man from malarious microorganisms suggests that other 

 germs and their products may have a similar effect in the lower 

 animals but nothing certain is known as to the true cause. 



Apart from mulanosis, it is not known that this pigmentation 

 of the hepatic cells is of any essential pathological importance. 

 It is important however for the veterinarian to be acquainted with 

 the condition, that he may intelligently deal with such lesions 

 whether seen in ordinary post mortem examinations, or in the 

 course of meat inspection. 



DILATATION OF THE GAI^L BLADDER AND BILE 



DUCTS. 



Causes : obstruction of common bile duct, distoma, round worms, 

 taemiae, gall stones, encrustations, inflammations, tumors, cicatrices, hy- 

 datids. Congenital absence. Ducts stand out on liver. Symptoms of 

 colic, icterus, bile poisoning, marasmus. Treat the causative conditions. 



This may occur in all our domestic animals except solipeds in 

 Which latter there is no gall bladder. 



Causes. Any serious obstruction to the discharge of the bile 

 into the duodenum may cause it. The presence of trematodes, 

 nematodes, or even taeniae in the ducts, gall stones, , incrusta- 



