ENTOZOA IN THE BILIARY PASSAGES. 113 



Chapter XIII. 



AFFECTIONS PEODUCED BY THE PBESENCE OF 

 ENTOZOA IN THE BILIAEY PASSAGES. 



The fact tliat entozoa sometimes exist in the biliary- 

 passages was unknown to the ancients. Gabucinus, 

 who, in a work published in 1547, mentions worms 

 similar in appearance to gourd seeds, which he found 

 in the livers of sheep and of goats, was probably the 

 first observer of entozoa in the biliary ducts ; the 

 worms of which he speaks were most likely a species 

 of Distomum.^ 



Certain classes of animals are very subject to 

 biliary entozoa, whilst others are wholly exempt from 

 these parasites ; the herbivora, and especially rumi- 



* The animal which ia most subject to this species of worm is 

 the sheep, in which the presence of the distoinum hepaticum, or 

 Liver Fluke, gives rise to the very destructive disease known as 

 Watery Cachexia, or more commonly as the Rot. The great 

 prevalence of this disease amongst sheep which are kept in wet, 

 marshy meadows, and particular!}' where stagnant water abounds, 

 points plainly to the means of prevention ; and it has been 

 practically shown that good and efficient drainage, with the 

 occasional removal of the flock to a dry, upland pasture, suffices 

 to maintain the sheep in a sound state upon farms where, pre- 

 viously to the drainage, it was impossible to graze sheep for many 

 continuous weeks without their becoming affected with the rot. 

 The impoverishment of the blood, in consequence of large quan- 

 tities of serum being drained away by the bowels, brings on a 

 dropsical condition, of which the sheep eventually dies. The 

 great importance of this disease will be understood, when it is 

 stated that the author of the " Treatise on the Sheep," in the 

 " Library of Useful Knowledge," estimates the yearly mortality 

 from it at one million of sheep and lambs in this country alone. 



I 



