The Rot ill Slicep. 
137 
as bluish-wlutc lines, more or less continuous, runnings by the side 
of the conj^ested blood-vessels, from the central part of the f^land 
towards its lower edf^e. In some places they arc rendered very 
distinct by projecting above the surface, being here dilated into 
pouch-like cavities. The coats of the ductus hepaticus, as also ol 
the ductus communis cholcdochus, are not unfrcquently so thick as 
to be upwards of ten times their normal substance, and like- 
wise so hard as to approach the nature of cartilage. 
On slitting up the ordinary biliary ducts, as we approach the 
smaller branches, this hardness increases, and the coats are 
found to be rough and uneven, arising from calcareous deposits 
— phosphate of lime and magnesia — within their tissue. It 
is this which gives the gritty feel to the surface of the liver, 
and imparts a crackling sound on cutting through its substance. 
Within the ducts we encounter numerous distomata, which 
are often here and there, and especially in the pouches, so 
closely packed as to block up the passage. Their number, how- 
ever, is liable to great variation, and, it has been rightly asserted, 
is not always in proportion to the extent of the structural 
changes in the liver. No doubt secondary causes play a not 
unimportant part in these changes, and so also does time ; but 
nevertheless the lesions of the liver are upon the whole so 
peculiar that, were no entozoa present, a pathologist would 
ascribe them to such a cause, and none other. Distomata will 
often quit the liver by passing into the intestinal canal through 
the ductus communis choledoc/ius, especially when the entire struc- 
ture of the organ has become impaired. Their food is the bile, 
and the more this is changed in quality, which is always in. 
proportion to the extent of the structural disease of the liver, 
the less suitable it will be for their support. Besides this, these 
entozoa, in common Avith all other creatures, have their ordi- 
nary limit of life, and, be this what it may, it is not unrea- 
sonable to suppose that their apjiroaching dissolution may at 
times possibly be an additional reason for their quitting the 
biliary ducts. 
We have frequently met with dead flukes in the intestines 
and sometimes in the liver, and occasionally have found them 
forming the nuclei of biliary concretions. One remarkable 
instance of this was a short time since brought to our notice, 
where the concretion was as large as an ordinary hen's egg, and 
when broken up was found to contain about a dozen dead 
flukes. It was lying in a pouch-like cavity of one of the 
biliary ducts. 
Another reason must be named as explanatory, perhaps, of the 
cause of but few flukes being met with in the biliary ducts, when 
the extent of the lesions of the liver does not bear a comparison 
