POLYSACCHARIDE-SPLITTING ENZYMES 313 



technique developed by two of them (Francis and Terrell 476 ), who 

 had found that by intratracheal or intrabronchial inoculation of 

 Type III cultures it was possible to produce in monkeys of the 

 Cynomolgos species an experimental pneumonia, which in its clini- 

 cal aspects resembled pneumococcal lobar pneumonia in man. The 

 authors used enzyme preparations made in the manner already de- 

 scribed, which varied in potency from two to twenty units per 

 cubic centimeter. They began the enzyme treatment within the first 

 three days after inoculation, administering the enzyme prepara- 

 tions intravenously usually in doses of ten cubic centimeters each, 

 with additional treatments as often as three times daily, either in- 

 travenously, intraperitoneally, or by both routes simultaneously. 

 Francis, Terrell, Dubos, and Avery purposely made no attempt to 

 ascertain the minimal amount of enzyme required in individual 

 monkeys but, rather, they employed the treatment intensively until 

 the result was assured. Moreover, they selected for enzyme treat- 

 ment the sickest monkeys among those infected, since this plan 

 would reduce the factor of natural recovery from the infection as 

 well as put the enzyme to the severest test. 



The accompanying photographs show the effect of pneumonia 

 on the lungs of a monkey that had been treated the first day after 

 infection, as follows : 



1. Control. Before inoculation (December 19). 



2. Nineteen hours after infection and seven hours before the first 

 treatment (December 20), showing well localized consolidation in lower 

 half of the right upper lobe. 



3. Second day (December 21), showing extension of pneumonia 

 throughout right upper lobe. 



4. Third day (December 22), showing increased density of the 

 shadow over the right upper lobe, but no evidence of further spread. 



5. Fifth day (December 24). Resolution of the pneumonia has be- 

 gun, as shown by the decrease in density and beginning aeration of the 

 area. 



6. Tenth day (December 29), showing complete resolution of the 

 pneumonic shadow. 



