686 REPORT OF THE COMMISSIONER OP AGRICULTURE. 



Plate VI. —Coagulation necrosis in the liver of rabbits inoculated with cultures of 

 hoff-cliolera bacteria. 

 Fig. 1 . — CepJialic aspect of the liver of a rabbit wliich was found dead on the sixth 

 da}' after inoculation. The lighter spots are groups of acini destroyed by 

 tlie growtji of bacteria. The larger patch to the left shows groups of 

 acini in which the necrosis has involved only the peripheral zone of the 

 acini. 

 Fig. 3.— Liver of rabbit which died on the eighth day after inoculation. The 

 caudal aspect is shown with two extensive patches of commencing ne- 

 crosis. In both only the peripheral zone is involved, giving the discol- 

 oration a mottled appearance. 



Plates VII to IX inclusive. — Photo-micrographs of the bacteria producing hog- 

 cholera and swine-plague. Made with the Zeiss camera, using the new 

 Vj apochromatic homog. immersion objective, projection ocular No. 4. 

 Magnification 1,000 diameters. The prepai-ations, stained either in Bis- 

 marck brown or fuchsin, were mounted in Canada balsam. Illumina- 

 tion from an incandescent electric lamp. 



Plate VII, Fig. 1. — Bacterium of hog-cholera. Cover-glass preparation from the 

 liver of a rabbit inoculated with cultures from Illinois. Stained for one 

 hour in an aqueous solution of Bismarck brown. 

 Fig. 2. — Liquid culture of the bacterium of hog-cholera from Illinois. Stained 

 in Bismarck brown. 



Plate VIII, Fig. 1. — Bacterium of hog-cholera from Nebraska. From a culture in 

 beef infusion less thaii twenty-fovir hours old, inoculated from a colony 

 on a gelatine plate. Stained for one hour in an aqueous solution of Bis- 

 marck brown. 

 Fig. 2,— Micrococci of swine-plague. From a culture in beef infusion about 

 twenty hours old. This culture was obtained from a gelatine tube cult- 

 ure of effusion and plastic exudate in the pleural cavity. The lungs were 

 extensively hepatized. Stained for one hour in aniline water fuchsin. 



Plate IX, Fig. 1. — Cover-glass preparation fi-om the liver of a rabbit inoculated with 

 a bit of lung tissue obtained from an outbreak of swine-plague in Iowa, 

 January, 1887. Stained in Bismarck brown for one hour, decolorized in 

 ^ per cent, acetic acid for a few juoments. Note the polar stain. 

 Fig, 3, — Cover-glass preparation from the blood of a pigeon inoculated from a 

 culture of the microbe of swuie-plague from Iowa. Stained in aniline 

 water fuchsin. 



