1897] 



MICROSCOPICAL JOURNAL. 



345 



others connected with water-works to whom tlie htudy 

 ofalgsB and infusoria would be of much value, the writer 

 has tried to reduce the Sedg'wick-Rafter method lo its 

 simplest possible elements in order that it may be more 

 generally used. Furthermore, it is often necessary for 

 the sanitary biologist to be provided with a portable out 

 fit for work in the field. There are many fragile organ- 



i^OO 



isms which will not hear transportation to the laboiatory. 

 Uroglena, for example, a very important and troublesome 

 organism found in water supjilies, <i;oes to pieces com- 

 pletely when kept for n slioii time in a st()[)[»ered bottle. 

 It is, therefore, necessnry lo make the examination of 

 water immediat«dy after tlie coUection of the sample. 

 The chief modilication of the method for fieM worK 



