BUREAU OF ANIMAL INDUSTRY. fil5 



bacterium liad also entered the blood was sliovvn by two pure cultures in beef in- 

 fusion obtained from the spleen. A gelatine culture from the liver contained about 

 6 or 7 colonies. 



No. 350 was a more typical case, and demonstrated the severe local effects of the 

 bacterium much better, since the animal lived longer. It ate fairlv well until the 

 fourth day, when its appetite gave way and diarrhea set in. From this time it gi-ew 

 w-ealc and thin, being scarcely able to walk. It died on the tenth day after feeding. 

 The lesions of the alimentary ti'act were exceedingly grave. Beginning with the 

 stomach, the mucous membrane was dotted with closely set elevated masses as large 

 as spUt peas, and larger patches of a whitish viscid substance, made up entirely of 

 cellular elements (diphtheritic?). When removed, a raw depressed surface was ex- 

 posed. The membrane itself was pale. Besides a general injection of the iliem, 

 Peyer's patches were more deeply congested, and the uppermost covered with a thin 

 yellowisn film, not removable, and most likely dead epitheUum. In the caecum and 

 colon the mucosa was superficially necrosed, and converted into a continuous layer 

 of a dirty whitish mass about !•"■" thick. The walls of the mtestine were greatly 

 thickened and very friable. 



Microscopic sections showed an extensive-cellular infiltration of the submucous con- 

 nective tissue which had separated the masses of fat cells, concealed the connective 

 tissue fibers, and caused a great thickening of the entii-e layer. The mucosa itself 

 was greatly altered. The surface was necrossed and converted into an amorphous 

 mass. In some places the necrosis involved the entire depth of the cryjits of Lie- 

 berkiihn, a series of strite indicating then- former existence. Those whose epithelium 

 still remained were plugged %vith a cyhndrical mass, filled with broken-down nuclei. 

 The bacteria had exerted their poisonous effects from the surface of the mucosa to- 

 wards the depths, destroying the surface epithelium and glandular sti'uctures and 

 involving secondarily the submucous layer. Near the rectum this continuous mass 

 of dead tissue was replaced by isolated ulcers embedded in an intensely reddened mu- 

 cosa. Plate II, taken from another case, illustrates well the superficial death of the 

 mucosa. The ileo-ca3cal valve was much swollen, but the necrosis did not extend 

 into the ileum, although there were a few ulcers near the valve, and the epithelium 

 had a pale, liisterless aspect, as if dead. The Uver was fiUed with blood, which 

 readily clotted as it flowed from the cut surface. Spleen congested and but slightly 

 enlarged. Lungs hypostatic. The lymphatic glands in general not much affected. 

 Two liquid cultures from the blood were turbid next day, and contained the hog- 

 cholera bacterium only. In a gelatine tube culture from the liver about a dozen 

 colonies developed in each needle track. 



No. 342, which was fed with the same quantity of culture liquid but was not de- 

 prived of food previously, was somewhat ill on the following day. It recovered, 

 however, and continued apparently well for several weeks. It began thereupon to 

 grow tliin and weak. On January 26 it was no longer able to rise, and was there- 

 fore killed for examination, in order to conclude the exijeriment. On opening the 

 abdominal cavity it was at once jDerceived that the animal had been suffering from 

 a very intense disease of the large intestine, a portion of which was firmly attached to 

 the bladder. When dissected out and slit open, the mucous membrane of the caecum 

 and colon was found replaced by a brownish friable layer of necrosed tissue. The 

 wall of the intestine was infiltrated to such an extent that it was nearly ^ inch 

 thick, and so degenerated that the forceps easily tore through it. The thickness of 

 the walls prevented the intestine from collapsing after it was opened. Its only con- 

 tents was a brownish liquid mass. The glands of the meso-colon were very large, 

 some like horse-chestnuts. On section the entire tissue was very pale, almost 

 wliite. The spleen was somewhat enlarged; the malpighian corpuscles unusually 

 large and prominent on section. Lungs and heart normal; kidneys deeply reddened 

 throughout on section. 



This case is very interesting in completing the information gained by this feeding 

 experiment. No. 348, which had been fed with sodium carbonate besides being de- 

 prived of food, died three days after the ingestion of the culture. No. 350, which 

 was simply starved, died ten days thereafter, wliile No. 342, which ate the culture 

 without being previously starved, was dying on the thirty-fourth day. 



These results show how easily infection may occur by way of the 

 digestive system, provided the destructive action of gastric digestion 

 be prevented, as was done by starving and by the use of an alkaline 

 carbonate. 



They also indicate how purely local this destructive action may be. 

 Gelatine cultures from these animals showed that the internal organs 

 contained but very few bacteria. So few were they in fact that the 



