CHAPTER III 



PLATYHELMIA 

 Phylum PLATYHELMIA 



ClaSS TUBBELLABIA Types 



TBEMATODA Distoma 



CESTODA Taenia 



NEMEBTINEA 



THIS phylum includes the Turbellaria, the members of 

 which are often called Planarians and are distributed in fresh 

 water, in the sea and on land, and are only rarely parasitic ; 

 the Trematoda and the Cestoda, which are parasites ; and the 

 Nemertinea, which are found mostly in the sea, but occur also 

 in fresh water and on land, and are only rarely parasitic. 

 The first three could be defined as aproctous Platyhelmia, 

 for in them the intestine ends blindly ; and the nemertines 

 could be styled proctous Platyhelmia, as in their case the 

 intestine forms an anal opening at the posterior end. 



Distoma (Fasciola). The liver fluke, Distoma hepaticum, 

 of the sheep and other ruminants is usually easily obtained 

 during the winter months from the liver of the sheep. It is 

 of economic importance, producing the disease distomatosis, 

 better known as liver disease or liver rot. 



The adult worm is flat, and fluke or flat-fish like in shape, 

 and is half to one inch in length. Large numbers may often 

 be obtained from the bile tubes of the liver of the sheep, and 

 the species has been recorded also from the ox, goat, camel, 

 and wild ruminants, even from the horse, pig, and elephant, 

 and it has been found in man. Another species, D. lanceo- 

 latum, has been found in the same or similar hosts. Both 



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