THE BACTERIOLOGICAL EXAMINATION OF THE BLOOD I39 



I and 2. Streptococci and Staphylococci. — These are found in cases 

 of septicaemia, pyaemia, ulcerative endocarditis, etc. ; they always 

 indicate an extremely bad prognosis. The chief importance which 

 attaches to the discovery of these organisms is that it absolutely 

 settles the diagnosis (always provided that there are no errors in 

 technique), and that it indicates whether the use of antistrepto- 

 coccic serum is advisable or not ; it is useless in cases of septi- 

 caemia, etc., which are not due to streptococci. 



A word of warning is necessary in the interpretation of results 

 which indicate that staphylococci are present in the blood. These 



Fig. 32. — Spirillum of Relapsing Fever. 



organisms are constantly present in the skin, and may be found in 

 film preparations or in cultures, unless rigid antiseptic precautions 

 are taken. Streptococci may also occur as contaminations of 

 cultures, but rarely occur in film specimens. 



3. Anthrax Bacilli. — These may be detected with ease and 

 certainty, but they are never found in the blood until it is too 

 late to save the patient. 



4. Tubercle Bacilli. — These are only present in very scanty 

 numbers, and are very difficult to detect. The diagnosis of 

 miliary tuberculosis is to be made by other methods, chiefly by 

 that of exclusion^ 



5. The pneumococcus is found in severe cases of pneumonia 

 (probably it might be found in most cases if a sufficiently large 

 quantity of blood were examined) and in septicaemia and ulcerative 



