6 WOUND INFECTION 



condition where one species may be responsible for the tissue 

 changes, although other bacteria are present but only in an 

 accidental or passive way. 



4. Through the generative organs. Infection of the 

 reproductive organs takes place in certain instances where they 

 are the seat of the disease. This is especially true in case of 

 maladie du coit. 



5. Throtigh the agency of insects. Some insects carry the 

 virus of certain diseases from the infected and introduce it into 

 the susceptible individuals. Thus the mosquito carries the 

 Plasmodium of human malaria, the cattle tick the piroplasma 

 of Texas cattle fever, and flies are often the introducers of 

 pathogenic bacteria, such as those of anthrax. In certain 

 instances, as with malaria, a part of the life cycle of the micro- 

 organism takes place in the body of the carrying insect. 



6. Transmission of the virus from the parent to the fetus. 

 Occasionally the young of diseased parents are born infected 

 with the disease with which one or both of its parents were 

 suffering. In these cases the specific bacteria were transmitted 

 either from the sire at the time of coition, or later to the fetus 

 in the uterus from the dam. It is important not to confuse 

 these rare cases with those in which the offspring are born 

 uninfected but subsequently contract the disease. Many of 

 the so-called hereditary diseases are the result of post-natal 

 infection. 



§ 4. \A^ound Infection. Wound infections are the direct 

 results of the entrance of certain microorganisms into trau- 

 matisms and operative incisions. They fall very naturally 

 into two classes: 



1. Those infections producing local, acute or more 

 chronic inflammatory processes usually leading to suppuration 

 and finally healing by granulation. This is the form most 

 frequently encountered clinically. The tissue changes are 

 those of acute or chronic inflammation. 



2. Infections which may in the beginning appear like 



