ERIK ZEUTHEN AND OTTO SCHERBAUM 



rate of multiplication in the hours after heat treatment was easily demonstrated even 

 without dilution. 



Dr. Hoff-Jorgensen kindly made some DXA determinations for us using the method 

 he is describing in this symposium. The data are included in Table I together with 



Table I 



* DXA fog.) per /il. medium: o 01-0 015. 



cell counts and measurements of total cell volume per unit volume of the culture. 

 The culture medium itself contains some DXA, but in concentrations of only 1-2 per 

 cent, of what is found in the cells. We consider it most likely that the DXA in the 

 cells represents synthesis and not just accumulation from the medium. 



(a) normal 



(b) heat-treated 



Figure 8. 

 150 



