• 



Fig. 1 (Pollock). Single deep colonies of Bad. 

 coli mutabile orowing in lactose-aoar. X 80. 

 a. From Lac " inoculum. 7 days" incubation. 

 h. From Lac+ inoculum, .'j days" incubation. 

 c. From Lac~ inoculum. 9 days" incul)ati()n. 



[fitcing page 26 



