SCHMIDT 



Dr. John L. Riggs of the University of Michigan, using 90 per cent 

 Eagles BM and 10 per cent calf serum as the growth medium. For 

 maintenance, the calf serum was reduced to 5 per cent. The same 

 growth and maintenance media were used for the cultures of the 

 RA strain of human amnion cells. 



The specific viral agents used were the D'Amori strain of ECHO- 

 6 virus and the Nancy nicKo strain of Coxsackie B-3, 



Bacterial Studies 



Investigations were made of the normal intestinal flora of 15 adult 

 ground squirrels both in the active state and foUcwing periods of 

 deep hibernaticn. Fresh fecal droppings were collected on filter pa- 

 per, and those contaminated with voided urine were excluded. Speci- 

 mens were kept at 4° C until processing, which took place within 2 

 hours after defecation. The droppings from an individual animal 

 were weighed and combined with an equal weight of sterile distilled 

 water. From this a uniform suspension was made with the aid of a 

 sterile glass rod. Part of the material was used for the determina- 

 tion of the per cent moisture and another portion for the preparation 

 of cultures. Triplicate cultures were inoculated from serial 10-fold 

 dilutions (10" to 10~ ) of the specimens, and the results obtained 

 were calculated as the number of organisms per gram dry weight of 

 fecal material. Quantitative determinations were made of the con- 

 form bacilli, fecal streptococci, and psychrophilic organisms, in 

 addition to a total viable aerobic cell count. The coliform bacilli 

 were cultured on (Difco) eosin methylene blue agar at 37° C. The 

 plates were seeded with 0.1 ml of the appropriate dilution which was 

 then spread evenly over the surface of the agar with a bent glass 

 rod. The inoculum was dispensed with a sterile 0.1 ml pipette. Using 

 this technique, well-isolated colonies were consistently obtained. 

 All gram negative rods yielding lactose- positive colonies within 48 

 hours were arbitrarily considered to be coliform bacilli. 



For the enumeration of the psychrophiles, (Difco) tryptone glucose 

 extract (TGE) agar was employed. Pour plates were prepared using 

 an inoculum of 1 ml and the incubation was carried out at 2 C to 

 3° C for 14 days. Organisms producing a visible colony within 14 



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