120 ANNUAL REPORT OF THE Off. Doc. 



2. Sections were examined for the presence of the endothelial 

 cell proliferation of the blood vessels and lymph sacs around the 

 ganglionic nerve cells. 



3. Animal inoculation. 



The diagnostic value of the Negri bodies in rabies was greatly 

 strengthened by the work during the year. The ganglionic changes 

 were studied, and it must be said that the endothelial-cell-prolifera- 

 tion changes are of considerable value, particularly in those cases 

 where the brain tissue is somewhat decomposed and considerable 

 difficulty is experinced in the staining of the smears or section for 

 the demonstration of the Negri bodies. The ganglionic tissue does 

 not decompose as readily as the softer brain structure and in several 

 instances it was possible to make a diagnosis where the postmortem 

 changes made it dillicult to determine the presence or absence of 

 the Negri bodies. 



Tuberculosis. Fifty-seven specimens were received for examina- 

 tion, consisting chiefly of tissue or material from cattle. Four of 

 the specimens were from children. The object of the examination 

 was not only to confirm the suspicion of the disease but to determine 

 the type of the infecting organism. In each instance there was a 

 history of possible infection through milk from cows. It was pos- 

 sible to infect a calf with material in one instance, which was the 

 only one of the four which resembled the bovine type of the tubercle 

 bacillus. 



Of the 57 specimens, tuberculosis was demonstrated in 43; 14 

 were negative. The diagnosis was made as follows: 



1. Demonstration of tubercle bacilli in smears. 



2. Microscopic examination of tissues. 



3. Animal inoculations. 



Third method was used when the first and second were doubtful. 

 Glanders. 379 specimens were received for examination which 

 may be classified: 



1. Blood from horses and mules suspected of glanders. 



2. Pus from abscesses or nasal discharges. 



Of the 379 specimens received, 318 were of blood collected from 

 horses and mules suspected of glanders, or from horses or mules 

 exposed; 47 of pus, in which the presence of Bacterium Mallei was 

 demonstrated in 23, and not demonstrated in 24. 



The reason for the large number of blood specimens sent to the 

 laboratory during the year is, in part, due to the request that such 

 be collected from all horses under quarantine for glanders, enabling 

 us to thoroughly try out the glanders agglutination test. 



The test was carried out in each instance and carefully checked 

 with the record of the mallein test, if such had been made, and 

 whenever possible, an autopsy of the horse, under test, was made 

 and added to the result of any inoculation test that may have been 

 made with material collected from the animal before and after 

 death. 



The confidence in the diagnostic value of the glanders agglutina- 

 tion test has been somewhat shaken in this careful checking up and 

 at the end of the year, the test was merely regarded as an aid in 

 establishing a diagnosis and not to be depended upon entirely in any 

 one instance. Valuable statistics are at hand upon this subject 

 and can be gathered for publication with a little more experimental 

 work. 



