320 AGEICULTUEAL AND INDUSTRIAL BAOTEEIOLOGY 



because of a deficiency in immunizing substances, probably 

 in large part opsonin. Occasionally apparently the presence 

 of bacteria in a wound or in a boil is not sufficient to incite 

 the individual to the production of immune substances or 

 antibodies such as opsonin. In such instances, boils may 

 recur at frequent intervals and the individual is said to 

 suffer from furunculosis. Under such conditions it has been 

 found possible to use successfully vaccines prepared from 

 the organism causing the trouble in the particular individ- 

 ual. These are prepared by growing the bacteria on slanted 

 agar cultures, suspending in physiological salt solution, 

 destroying by heat. Subcutaneous injection of such a vac- 

 cine tends to incite the tissues to the production of suitable 

 antibodies. 



