92 IOWA ACADEMY OF SCIENCES. 



tends over such a longr period of time and rarely exists on but one farm in a neigh- 

 borhood, we are loth to accept the diagnosis of rabies. 



Thinking it was possibly a bacterial disease, I have made quite a thorough bac- 

 teriological study of the trouble. I have made cultures from the liver, spleen, 

 kidneys, blood, brain substance and brain serum. Some of them have been made 

 in the field and others in the laboratory from tissues carefully removed for that 

 purpose. For culture media, agar-agar, nutrient gelatine, blood serum, bouillon 

 and potato have been used. 



Culture tubes inoculated from the spleen, liver, blood and kidneys often remain 

 sttrile. In some instances organisms have been obtained from these organs, but 

 no one of these has been met with in a majority of the cases examined. From the 

 brain and brain serum, several chromogenic varieties have been isolated, some of 

 which have been obtained from more than one animal. Rabbits and calves have 

 been inoculated with bouillon cultures of those organizing with negative results. 



An organism not chromogenic has appeared in one or more of the culture tubes 

 from four different outbreaks. It has been obtamed from the brain, spleen and 

 liver. From its frtquency of occurrence it would seem possible that it may have 

 a casual relation to the trouble. Rabbits, calves and one dog have been inoculated 

 subcutaneously and intravenously with bouillon cultures with negative results, and 

 no organism so far observed has proven pathogenic. 



The organism last referred to is a micrococcus, considerably larger than the 

 most micrococci. In agar-agar stab-culture it develops slightly along the track of the 

 needle and extends slowly over the surface, forming a raised, soft, tenacious mass. 

 At first white, the growth gradually becomes dirty white or cream colored, border- 

 ing on brown. On blood serum the growth does not form a circular confluent 

 mass, but development occurs on the surface in lines extending in different direc- 

 tions from the seat of puncture. It grows better in bouillon than in solid media, 

 and does not produce gas in ordinary media. In bouillon no film forms on the sur- 

 face, but a sediment forms at the bottom of the flask which in time becomes quite 

 abundant. It grows at the ordinary room temperature, but faster in thermostat at 

 about 37°. In agar- agar I have observed in a few instances individual 

 colonies develop along the track of needle, which eventually became very dark 

 colored, almost black. 



Recently an outbreak of the disease near Greene, Iowa, furnished some material 

 for more experiments, and with the assistance of Drs. Moore and Kilborne from 

 the Bureau of Animal Industry, a yearling heifer was inoculated under the dura 

 mater — a piece of bone having first been removed with a trephine — with an emul- 

 sion of brain matter from an animal which died from the effects of the disease 

 On the nineteenth day after the inoculation the inoculated animal began showing 

 symptoms similar to those described heretofore. Death occurred on the sixth day 

 after the first symptoms were observed. A post mortem examination showed 

 much the same conditions met with in regular outbreaks. Before the death of the 

 animal, saliva was collected and a rabbit inoculuted inside the thigh under the 

 skin. This rabbit died in nine days. Inoculations have been made from both the 

 calf and rabbit brains, and it is hoped we will now be in a position to say whether 

 the disease is rabies or something else, 



