Quantitative Bacteriological Examination. 45 



laboratory is, however, always- great, and it is almost 

 impossible to secure proper conditions for iiicubation in 

 any temporary establishment. On the whole, the authors 

 are of the opinion that laboratory examinations are to be 

 preferred to those made in the field, if a laboratory can be 

 reached within twelve hours of the time of collection of 

 the samples. 



