23 



forming "bacilli were the most susceptible to the gut con- 

 tents of S. calci trans while the staphylococci were more 

 affected by the material from A. persicus . 



As to the properties of the active principle, Duncan 

 states: n **-*bactericidal action is greater and more 

 rapid at 37° C. than at room temperature. This action 

 is not accompanied by any visible bacteriolysis. The 

 bactericidal principle retains its activity unimpaired 

 for at least six months when kept in the dry state. It 

 is very thermostable, resisting temperatures as high as 

 120° C. It is not destroyed by tryptic digestion. It 

 is precipitated from solution with proteins by alcohol 

 or acetone, but is not itself affected by these reagents, 

 It is not soluble in the common fat-solvents, ether, 

 chloroform, alcohol, or acetone. By allowing it to act 

 upon repeated small doses of bacteria, it rapidly becomes 

 exhausted and it can be inactivated, possibly through 

 adsorption, by large doses of killed bacteria; even those 

 species which are not destroyed by it. It may also be 

 adsorbed in small amount by bibulous paper. It exhibits 

 none of the properties of bacteriophage, and it differs 

 from lysozyme. 



"Regarding the source of the active principle, there 

 is no doubt that it is formed in the stomach, but whether 

 as a secretion of the gastric cells or as a result of the 

 processes of digestion is not clear. (Nuttall, 1908), 

 showed that the destruction of Spirochaeta duttoni in the 

 gut of the bedbug was definitely related to digestion. ) " 



Surgical maggots . According to Livingston and Prince 

 (1932), as early as the sixteenth century Pare observed 

 that suppurating wounds in which blow flies had deposited 

 their eggs healed with unusual rapidity. Larrey, the 

 famous surgeon of Napoleon, observed that during the 

 Syrian campaign the presence of larvae in the soldiers ' 

 wounds enhanced the healing processes. Other early phy- 

 sicians noticed the relationship between maggots and the 

 healing of wounds. The real impetus to the study of this 

 relationship came with the observations of Baer (1929, 

 1931) who, during the first World War, noticed that men 

 wounded in battle and left unattended on the battlefield 

 for as long as 7 days before being taken to the dressing 

 stations frequently had their wounds infested with maggots, 

 These men had no fevers and did not develop infections 

 nearly as often as did those who had received early treat- 

 ment. He observed that after cleaning their wounds, in- 

 stead of pus and debris, they were filled with healthy, 

 pink granulation tissue. Baer concluded: 



