44 



STUDY AND IDENTIFICATION OF BACTERIA 



from that part of the field. In current movement all the bacteria 

 swarm in the same direction, going very fast at times, and then more 

 slowly. If in great doubt, the mounting of the organisms in a 2% 

 solution of carbolic acid will stop movement if it be true functional 

 motility, while Brownian and current movement are not interfered 

 with. In true motility bacteria move in opposite and in all directions, 



FIG. 9. Chart in use at the U. S. Naval Medical School. 



and move away from the place where first observed unless degenerated 

 or dead. 



At times we judge of motility by the presence of this characteristic in a few of 

 the organisms seen in the microscopic field, the vast majority of the bacteria not 

 showing motility. A source of error can be present when the bacteria are emulsified 

 in a drop of water which might contain motile bacteria. 



