616 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



microscope alone could not have demonstrated their presence, as they 

 could not be found on cover-glass preparations. 



Other successful experiments by feeding pure cultures will be 

 given in connection with a description of the bacterium from differ- 

 ent parts of the country. 



(c) Subcutaneous inoculation ivitli pure cultures. — The least suc- 

 cessful method of producing the disease is the subcutaneous inocula- 

 tion of pure cultures. In the report for 1885 at least three out of four 

 inoculations produced a rapidly fatal form of the disease. In the 

 numerous experiments to be described later, in which pigs were in- 

 oculated with cultures to determine whether any future protection 

 was thereby granted, only five died from the inoculation. In these 

 experiments two subcutaneous injections were practiced, a smpJl 

 quantity being followed by a larger quantity of culture liquid. The 

 deaths occurred from the first injection when this was made compara- 

 tively large; the second dose, which was usually quite large, was 

 borne without any ill effects. 



These successful inoculations, reported in extenso in another section, are briefly as 

 follows: No. 239, inoculated April 27 witli ^j" culture liquid, died May 2, only six days 

 after inoculation. Hemorrliagic condition of vital organs. Though seven others 

 were treated in the same way none took sick. It may be that in this individual the 

 needle entered a suijerficial vein, and in this way introduced the virus directly 

 into the blood. 



Nos. 204 and 213, inoculated April 12 with li" culture liquid, died eleven and seven 

 days after inoculation, respectively. In the former the mucosa of large intestine 

 was entirely necrosed. In the latter ulceration was just beginning. 



Nos. 208 and 209, inoculated at the same time with 1" of the same culture, died 

 fifteen and six days after inoculation respectively. Numerous extensive ulcers in 

 the large intestine of 208. In 209 general congestion and extravasation along di- 

 gestive tract and in internal organs. With each pak two others had been inoculated 

 without any untoward results. 



The local swelling at the point of inoculation is usually propor- 

 tionate to the quantity of culture fluid injected. The folloAving cases 

 show how large quantities may be borne without inducing the disease: 



Nos. 116 and 154 were inoculated February 8 by the subcutaneous injection of 3^«« 

 of the second culture from the spleen of No. 165 in beef-infusion peptone, one-half 

 being injected into each thigh. A very large swelling appeared at the seat of inoc- 

 ulation in No. 154, causing considerable lameness. March 4 this animal was killed, 

 although evidently not diseased. The inoculation tumor was over 1 inch long and | 

 inch thick; firm, yellowish-white, developed in the loose connective, and only 

 loosely attached to skin and subjacent mucular tissue. There was considerable serum 

 in the abdominal cavity, and the spleen was somewhat enlarged. In the fatty tissue 

 lining the dorsal wall of the abdominal cavity numerous worms were found (Sclero- 

 stoma pinguicola), occupying tunneled spaces in the fibro-adipose mass. No indi- 

 cations of hog-cholera. No. 116 was not affected. 



No. 181 was moculated February 13 with 7" of the second liquid culture from the 

 spleen of pig No. 159. "Within a few days the animal became lame, but this passed 

 away. At the seat of inoculation large tumors had developed, no doubt causing 

 the stiffness of the hind limbs. This animal was killed March 4. At each point of 

 inoculation were found firm fibrous masses, from 2 to 3 square inches in extent and 

 nearly an inch thick. No suppuration. There were no lesions pointing directly to 

 hog-cholera. There was, however, a considerable quantity of pale senim in the 

 abdominal cavity. Spleen enlarged; cortex of kidneys dull, thickened; lymphatic 

 glands of large intestine somewhat prominent, but pale. 



These animals may liave suffered from the absorption of ptomaines from the place 

 of inoculation, but dissemination of the bacteria through the internal organs evi- 

 dently did not take place to any extent. 



The failure to produce the disease in even a small proportion of 

 animals by the injection of liquid cultures raised the question whether 

 the cultivation in itself did not attenuate the bacteria. Consequently 



