Etiology. 609 



symptoms of a slight brain disturljance, and the micrococci were dem- 

 onstrated in the cerebro-spinal fluid ; while in a third, the injection was 

 followed by symptoms of sleepy staggers. Subdural inoculation into 

 horses caused severe meningo-encephalitis, the cocci being demonstrable 

 in pure culture in the exudate. 



Johne found diplococci in the cerebro-spinal fluid, and in one case 

 in the blood of diseased horses. The cocci measured 0.4 to 0.8 jn; and 

 some were free and others included within cells. After staining with 

 Ziehl's stain and washing with dilute acetic acid, the organisms showed 

 special shapes resembling coffee beans or wheat grains. They were not 

 constantly Gram-fast. 



The cultural characters resembled those of the Siedamgrotzky- 

 Schlegel organism and short chains were formed. Growth was partic- 

 ularly luxuriant in the condensation water of agar when the cultures 

 were incubated. This organism was called by Johne, the Diplococcus 

 intercellularis equi, on account of its morphological and biological re- 

 semblance to the causal organism of contagious cerebro-spinal menin- 

 gitis in man. Typical symptoms of Borna disease followed the sub- 

 dural inoculation of the organism into two goats and three horses. All 

 the horses recovered while the goats died. At the postmortem of one 

 of the goats a purulent and fibrinous spinal meningitis was discovered. 

 Similar diplococci were found by Marcq in diseased horses in Belgium, 



Organisms morphologically resembling the diplococcus of Johne 

 were found by Ostertag in cases of Borna disease. The organisms oc- 

 curred only in very small numbers, and were very rarely included with- 

 in cells. They were as a rule present in the subdural and ventricular 

 fluid of the brain and occasionally in the blood, liver and urine, but 

 only very exceptionally in the substance of the brain. On artificial 

 media short chains were formed; division was in two planes; the or- 

 ganism was non-motile, and Gram-fast. Growth on artificial media was 

 scanty, but it was particularly abundant in the condensation water of 

 agar. The organism grew equally well on acid and alkaline media. 

 In broth there was uniform turbidity, contrary to what is the case with 

 the streptococcus pyogenes. Gelatin was not li(iuefied. Multiplication 

 of the cocci occurred in water containing ammonia or nitrous acid. 

 The optimum temperature for growth was that of the body. Resis- 

 tance offered by the organism was slight, desiccation causing rapid de- 

 struction. The organism soon died in pure water, while they remained 

 alive for 4 months in moist substances. IMultiplication occurred in wa- 

 ter containing drainage from stables. 



The microorganism designated by Ostertag as Borna-Streptococ- 

 cus was pathogenic for the horse, but not for the laboratory animals. 

 Subdural inoculation into horses was promptly followed by the usual 

 symptoms. According to Profe, repeated intravenous inoculations at 

 short intervals caused a disease resembling Borna disease, while a sin- 

 gle inoculation or a number spread over a long time caused a condi- 

 tion that was not at all typical, and quite transitory. Goats and sheep 

 are susceptible to subdural inoculation, but not to so great an extent 

 as the horse. Cattle and pigs are refractory. The introduction of the 

 organism under the skin, into the nose, eye, ear or alimentary canal 

 is not followed by any symptoms in the horse. 



Streit isolated an organism closely resembling, and possibly iden- 

 tical with the streptococcus of Borna disease from a case of epizootic 

 cerebro-spinal meningitis in a horse in Ontario, as did also Grimm in 

 southern Germany, while Harrison observed a quite different organ- 



