64 REPORT OF THE BUREAU OF ANIMAL INDUSTRY. 



were the only organs examined bacteriologically. These notes 

 serve to supplement the autopsy notes in the reports for 1885 and 1886. 



In making cultures from the spleen the following method was usu- 

 ally adopted. At the autopsy the abdomen was carefully laid open 

 by first removing the skin and then cutting through the abdominal 

 muscles with flamed instruments. The flaps laid back brought into 

 view the spleen not touched as yet by any instrument. It was then 

 drawn out with flamed forceps, severed from its attachments with 

 flamed scissors and placed in a large bottle plugged with cotton wool 

 which had been previously subjected to a temperature of 150-160 

 C. for two hours. In this way it was taken to the laboratory and 

 either immediately examined or kept in the refrigerator below 55 F. 

 over night. In making cultures the spleen was placed on a sterile 

 glass support and the surface thoroughly charred with a red-hot 

 platinum spatula. This was always done, although seemingly un- 

 necessary when we consider the momentary exposure to the air in 

 transferring the spleen from the abdomen to the sterile bottle. It 

 may, however, destroy any bacteria which have entered the peri- 

 toneal cavity through ulcers. Through this charred area an incision 

 or rent was made and a platinum wire introduced, and then a tube 

 of gelatine or beef infusion inoculated with it. When roll cultures 

 were made a minute bit of spleen pulp was torn away from beneath 

 the charred portion and stirred about in the liquefied gelatine. From 

 this usually a second tube was prepared. Experience of past years 

 has shown that frequently this is not sufficient to insure the fertility 

 of the cultures. In chronic cases with the spleen but moderately en- 

 larged, hog cholera bacteria are found in very small numbers. In 

 such cases bits of spleen are cut out from the charred area with flamed 

 scissors and transferred to tubes of gelatine or beef infusion with or 

 without peptone. Such cultures rarely fail. It might be supposed 

 that the chances of accidental contamination are very great in this 

 process. But a long experience with spleens of healthy animals and 

 with organs in the study of other diseases has demonstrated the en- 

 tire safety of this procedure. Salmon culture tubes with bits of 

 organs in the bottom covered by nutrient liquids have.remamed sterile 

 for months in the laboratory. At present the Esmarch tube or roll 

 culture is indispensable in such cases. 



In nearly all the cases examined both liquid and gelatine cultures 

 were made. The former permit a diagnosis on the following day, 

 while the latter require at least two days, usually three or four, be- 

 fore a reliable diagnosis can be made. The cultures were always 

 examined unstained in a hanging drop, as the bacteria in this way 

 are not deprived of their power of motility, which is one of the im- 

 portant diagnostic characters. Staining cultures was also resorted 

 to, but it adds little information to that gained by a careful exami- 

 nation of the hanging drop. When gelatine cultures were examined 

 the bacteria were always mixed with some sterile beef infusion to 

 bring out their motility. 



In a number of cases rabbits were inoculated directly from lung 

 tissue. A small bit, about one-half centimeter cube, was torn up with 

 flamed forceps in a flamed watch-glass containing some sterile beef 

 infusion, and the turbid fluid injected beneath the skin of the thigh. 

 The syringe used was an ordinary hypodermic syringe carefully dis- 

 infected by 5 per cent, carbolic acid above and below the piston for 

 one-half hour both after and before use, and each time thoroughly 

 rinsed in boiling water. As hog cholera bacteria are destroyed by a 



