WOUND INFECTION 9 



are rarely found in acute wound infection lesions excepting 

 in specific diseases which they cause and where their entrance 

 is through injuries or by means of the bites of insects. Many 

 of the specific pathogenic bacteria may be introduced through 

 wounds. As a rule, it seems to be true that in the domesti- 

 cated animals, as in man, the pyogenic bacteria are the most 

 common and important wound infecting microorganisms. In 

 open wounds these are, of course, associated with a very large 

 number of ordinary saprophytic bacteria. Frequently in 

 closed lesions nonpathogenic organisms are present in addition 



Fig. 3. Streptococcus pyogenes. Draiving made from a cover-glass 

 preparation from a bouillon culture. Highly magnified. 



to the seemingly causative factors. It is worthy of note that 

 it appears to be impossible to predict from the general charac- 

 ter of the lesions, the kind of bacteria which are producing 

 them, except it be in case of infections like tuberculosis or 

 actinomycosis. These bacteria are usually recognized without 

 trouble in cover- glass preparations made from the lesions. 



