THE GROUSE DISEASE 





manner with the heart's blood ; they all remained 

 sterile on incubation and free of any growth. The 

 heart's blood of at least half-a-dozen grouse dead 

 of the disease, or killed while diseased, was thus 

 examined, but no bacteria could be discovered in it. 

 Lungs, liver, and kidneys were taken out from the 

 animals after death, and were cut into small bits and 

 preserved in spirit or Muller's fluid. Sections were 

 then cut and stained with aniline dyes and mounted 

 in the usual way, but here also no bacteria could 

 then be found. This was the position of things 

 which I described in my first report in the Field in 

 July 1887. I have in 1888, 1889, and 1890 exam- 

 ined many birds that died of the disease in April, 

 May, June, or July ; and also in them I could not 

 discover in the blood of the general circulation, either 

 in cover-glass specimens or by cultivation, any bac- 

 teria. From this I am enabled to say that in a large 

 number of the grouse dead of the grouse disease in 

 the spring and summer, — that is, dead with the char- 

 acteristic pathological appearances of the lungs and 

 liver, — the blood of the general circulation does not 

 contain any microbes discoverable by the cover-glass 

 or culture test. In 1888 therefore I directed my 

 attention to examining in the same way, in the fresh 

 condition, the tissue of the lung and liver ; and, 

 with the exception of one or two doubtful cases, in 



