"GROUSE DISEASE" 199 



" I have seen a few cases in which htemorrhage has taken place, showing 

 itself in the form of petechi^e in the peritoneum." * 



These appearances which Professor Klein believed to be diagnostic of the 

 acute infectious pneumonia are summarised on page 44 of his book, as follows : — 



" The congestion of one or both lungs, the congestion of the liver, the small dark 

 spleen, and the patchy redness of the intestine and the peritoneum," and one may 

 add, the presence of the specific bacillus in the lung and liver of affected birds. 



Although the bacillus is not present in the circulating blood of birds affected 

 during the spring and early summer outbreaks, appearing then mainly in the 

 lungs and liver, they are to be found, he tells us, in the circulating 



Pl'GSGllC© 



blood of birds that have died in the autumn and winter. He believes, of bacillus 

 moreover, that the latter are the sporadic cases which keep the disease 

 lingering through the winter, ready to break out in a spring or summer epidemic, 

 though the vitality of the microbe is such that it probably requires no such 

 active assistance from individual birds. 



It will be seen that it appeared impossible for the Committee to accept 

 unconditionally the views of any of their predecessors in the work ; but it 

 seemed equally impossible to discredit altogether the reliability of detailed 

 observations made by many workers of high standing. At this stage of their 

 investigation the Committee still believed that Klein's " Grouse Disease" was an 

 established fact (though his diagnosis might require revision), and spoke of it as 

 the "true epidemic Grouse Disease," or "Klein's acute infectious pneumonia." 



At the same time, the Committee believed it to be an advantage for them 

 to see one disease at a time, and began to distinguish Cobbold's Strongylosis 

 as a specific disease apart from Klein's acute infectious pneumonia. 



The foregoing resume is necessary in order to show the position of the 

 controversy when the Committee of Inquiry was beginning its work. It 

 explains many of the unavoidable errors into which the Committee was 

 led by the inaccuracy of much that had been published on the subject. Even 

 Professor Klein's w'ork, accurate and painstaking as it was, and clear oause of 

 as were his published descriptions of whatever he himself saw, was P^°fessor 

 misinterpreted by him for the sole reason that bacteriology (a science ®''™'"- 

 of which he was one of the most honoured founders) was still in its infancy. 

 His deductions as to the disease being an acute infectious pneumonia due to a 

 specific bacillus have now been shown to be founded upon a misconception ; 



' Klein, "Grouse Disease," p. 19. 



