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IVAN C. HALL 



use of equal parts of veal extract seemed not to decrease the 

 volume of growth but we have adhered to the use of testicle 

 infusion alone. 



AGAR 



The amount of agar is important as shown in table 1. Media 

 were made from the same testicular infusion in four lots with 

 1, 2, 3 and 4 per cent agar. After sterilization the slanted tubes 

 were left in the incubator at 37°C. for three days to dry out 



TABLE 1 

 Optimum amount of agar 



* Patchy colonies respread on all tubes. 



Note. In this and other tables a "slight" growth approximates that of B. 

 influenzae upon blood agar; a "fair" growth corresponds to that of B. typhi upon 

 plain agar; "good" to that of B. coli; and "excellent" to that of Bact. pneumoneae. 



the surface of the slopes, a point shown to be necessary by ample 

 experience. The slopes were inoculated from 48 hours ascitic 

 agar cultures, incubated at 37°C. and observed daily. 



Soft testicular infusion agar has in our hands regularly yielded 

 less satisfactory results than that which was more firm and 

 less moist, a fact apparently at variance with the experience of 

 McCann (1896) working with cyst fluid agar, and Van Saun 

 (1913) with "salt free" veal agar. Firm testicular infusion 

 agar is moreover not only favorable for growth but facihtates 



