12 THOMAS SAY FOUNDATION 
can be washed out by swishing the net back and forth in the water. 
If made of strong material this net will stand considerable abuse. 
Transporting Live Nymphs. Since most of the stonefly nymphs 
live in moving and well-aerated water, they cannot be transported 
Fig. 3. Sieve net for collecting stonefly nymphs. 
nor kept for any length of time in water-filled containers unless 
the water is continuously aerated. A minnow pail with a com- 
pressed-air chamber, from which a small stream of air bubbles 
passes through the water, has been found very useful in carrying 
nymphs from the field to the laboratory. A very satisfactory meth- 
