12 THE INTERNAL PARASITES OP 



intestinal passages, all the organs here represented refer 

 to the system in question. The parasite is shown (Fig. 3) 

 as if viewed from behind, and therefore, as in the previous 

 figure, the so-called ventral sucker has not been traced. 

 It is a true distome, and, as such, forms a very good 

 type of the family. 



This elegant little parasite is more frequently found in 

 the ox than in any other host, and has hitherto been 

 observed only in a very limited number of different 

 bearers. It has been detected occasionally in the sheep, 

 and more rarely in the red and fallow deer. If the prac- 

 tical question be asked, u Is it capable of giving rise to 

 disease V I have no hesitation in replying affirmatively. 

 Not that I am aware of any case of " rot " in bullocks 

 having been recorded as coming from this source, but 

 that I know it has occasioned bad results in the human 

 subject, and I have myself witnessed the most serious 

 disorganisation produced by a species of liver fluke of 

 even smaller dimensions. In my general treatise on 

 Entozoa there is a case, recorded from Leuckart, which is 

 most instructive. The " host " in this instance was a 

 young girl, the daughter of a shepherd, who contracted 

 the disorder while attending her father's sheep. She 

 died from emaciation and an enormously enlarged liver, 

 produced by the action of this parasite. After death it 

 was found that the contracted gall bladder contained 

 forty-seven examples of this worm. If, therefore, disease 

 and death may be occasioned by the Distoma lanceolatum 

 in the human subject, it is easy to believe that this para- 

 site must be more or less injurious to cattle and sheep 

 when present in any considerable numbers. As before 

 remarked, I have seen the liver ducts of a non -ruminating 

 animal inflamed and thickened to an extraordinary degree 



