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tered at every step on the marshy plateau of La Bresse, and 

 they have principally infected those to which by preference 

 aquatic birds repair, especially ducks, which one meets 

 with by thousands. So far as we know, the parasites have 

 never been found in either of the rivers of this region." 



After remarking upon the variable number of parasites 

 found in each fish commonly four or five, but sometimes 

 as many as fifteen M. Duchamp continues : " As will be 

 easily understood, the presence of such guests in the midst 

 of delicate organs could not fail to produce a series of 

 morbid phenomena and to give birth to grave anatomical 

 complications. Also, with a little practice, it is easy to 

 diagnose the existence of the ligules, unfailingly. The 

 abdomen of a tench bearing these parasites presents an 

 unusual development, a true tumefaction (ballonnemenf), On 

 applying the index-finger to the lower surface of the body 

 between the pectoral and abdominal fins, an evident fluc- 

 tuation is felt. At the opening of the abdominal cavity 

 there escapes a noticeable quantity of liquid which is some- 

 times strongly sanguineous, sometimes thick and purulent, 

 but in both cases always carrying with it large white 

 flakes." 



After remarking upon the coagulable character of 

 this fluid and upon the leucocytes, blood corpuscles, and 

 other elements shown by the microscope, Dr. Duchamp 

 observes that "the intestinal circumvolutions, the ovaria 

 and milt glands form a single mass, in the centre or near 

 the surface of which the ligules are found often shut in by 

 peritoneal bands." It is added that the peritoneum is 

 thickened and covered by a layer of false membranes, but 

 there is no trace of inflammation of the liver. In short, the 

 affection produced by the parasite is, according to Duchamp, 

 a veritable chronic peritonitis. 



