THE BOUNDWORMS OF DOMESTIC SWINE. 35 



Spiroptera strongylina fastened partly in the stomach wall, partly in the pseudo- 

 membrane. In addition to these lesions, dark red spots the size of a penny were to be 

 seen, corresponding to which were numerous openings the size of a needle prick, 

 through which projected the bodies of the nematodes. 



While no data are at hand regarding the effect of Arduenna dentata 

 on its host, hi view of its close similarity with Arduenna strongylina 

 and the fact that both species are parasitic in the stomach, it may be 

 assumed that the former species is as injurious as the latter. 



Railliet and Henry (19 lib) report that the stomach of a sow from 

 Madagascar from which specimens of PJiysocephalus were collected, 

 presented a very intense gastritis with a quantity of small elevations 

 on the mucosa. 



The information and material supplied by the inspectors of this 

 bureau have shown that lesions of a nature similar to those described 

 by Von Ratz are frequently associated with the presence of Arduenna 

 strongylina in this country. 



The inspector in charge at South Omaha reported that "Ten per 

 cent of the affected stomachs show a highly inflamed zone surround- 

 ing the infested area, and hi a few instances considerable ulceration 

 exists." The inspector in charge at St. Louis was of the opinion 

 that "they produce no apparent lesions." The inspector in charge 

 at Chicago forwarded, in addition to the loose specimens already 

 mentioned, several pieces of hogs' stomachs showing the worms in 

 situ. The heaviest infestations were found hi portions from the 

 pyloric end of the stomach, which in one instance presented the 

 folio whig appearances: A piece of stomach from the pyloric end 

 about 21 cm. wide by 20 cm. long contained a cluster of worms buried 

 in a glairy mucous mass of yellowish color firmly attached to the normal 

 mucous membrane, and forming, hi the opinion of pathologists in the 

 Pathological Division of this bureau, to whom the tissues were referred, 

 a pseudomembrane of necrotic tissue. Several such worm clusters 

 were observed on the portion examined, the worms in nearly every 

 case being buried in a mass of mucus, and appearing as bright red 

 lines in the yellowish mass. (See PI. I.) In places the necrotic 

 tissue had apparently sloughed off, leaving deep, red, depressed areas 

 of irregular shape. These areas varied in size from a few millimeters 

 to 2 or 3 centimeters in diameter. The same lesions could be observed 

 under the necrotic tissue when this had been removed with forceps. 

 The condition was described by one of the pathologists as "undoubt 

 edly ulcerous." 



It was suggested by the pathologists who examined the material 

 that the pseudomembranes might have been caused by Bacillus 

 necrophorus gaining an entrance to the submucosa as the result of the 

 piercing of the mucous membrane by the parasitic worms; examina- 

 tions of scrapings from the stomach lesions revealed a few specimens 

 of the bacillus. As explained by Mohler and Morse (1904), this 



