BUREAU OP ANIMAL INDUSTRY. 683 



ease, involving tlie lungs only. There are no lesions of the intestinal 

 tract. Is, then, this ScJiweiiieseuche the same as the pneumonia 

 which we have found ? Let us compare for a moment the microbes. 

 Both destroy mice, the microbe of Schwemeseuche more speedily and 

 invariably. The same may be said of rabbits, Inoculation on the 

 ear caused death in one to three days, according to Schiitz. The 

 same mode of inoculation produced death with the American form 

 in nine days, and even subcutaneous inoculations do not prove fatal 

 in less than three days.* Guinea-pigs are only in part susceijtible 

 to both microbes; pigeons to both when large quantities of virus 

 are introduced into the system. Fowls are killed by the American 

 form in large doses. Schiitz does not report the use of large doses 

 with these birds. Both produce extensive pathological changes at 

 the point of inoculation in the susceptil^le animals. 



When we come to their effect upon pigs after subcutaneous inocu- 

 lation marked differences are manifested. Pigs inoculated by Schiitz 

 died from one to three days after inoculation. Besides producing 

 rather severe local reaction, the bacteria had multiplied in all the in- 

 ternal organs and were easily demonstrable in cover-glass prepara- 

 tions. Those inoculated with the American form at the experimental 

 station died in from one to two weeks. The quite constant patho- 

 logical change consisted in acute contraction or cirrhosis of the liver, 

 followed by jaundice. The bacteria had been meanwhile destroyed, 

 for cultures from such cases remained sterile. Feeding either in cult- 

 ures or in animal tissues failed to produce the disease. Schiitz suc- 

 ceeded, however, in producing pneumonia from- inhalation of cultures. 

 Our experiment failed, perhaps, because the spraying was not con- 

 tinued long enough. 



These differences, apparently very wide, may after all dej^end sim- 

 ply upon a dift'erence m virulence; and it may be joossible for us to 

 obtain from other outbreaks a microbe which is as virulent as the one 

 described by Schiitz. There is every reason to believe that this mi- 

 rcobe loses its virulence very speedily in artificial cultures. This may 

 have modified somewhat the results, since several weeks elapsed from 

 the time the cultures were prepared from the affected animals to the 

 time when the pigs could be inoculated therewith. 



Schiitz t and others J are inclined to regard the microbe of Schtveine- 

 seuche identical with the one which has been found to produce septi- 

 caemia in ral^bits. In this connection it is of interest to mention 

 briefly some exi)eriments§ made with a microbe obtained from rabbits, 

 which seems to be closely related to, if not identical with, the microbe 

 of rabbit septic£emia as described by European observers, and may 

 perhaps be a modified form of the microbe found in pigs. This it re- 

 sembles in form and mode of staining at the two extremities, but it 

 is, as a rule, somewhat larger. It also differs in forming a more or 

 less complete membrane at the surface of the culture liquid two or 

 three days after inoculation. In its eft'ect upon animals, that upon 

 rabbits is especially characteristic. It destroys them within two days 



*The microbe obtained from Iowa is more virulent than this, and resembles more 

 closely the German form. These lines were %vritten before this had been investi- 

 gated. 



jLoc. eit. 



X Hu])pe: Ueber die Wildseuche u. ihre Bedeutung fur die Hygiene. Berliner kli- 

 nische Wochenschnft, 1880, No. 44. 



§For a detailed account, see the Quarterly Journal of Comp. Medicine and Sur- 

 gery for January, 1887. 



