16 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 39 



in the funnels within a day or two ; otherwise, considerable loss 

 of population occurs within the samples. If collected during cold 

 weather, they may be kept in cold storage for a week or two 

 with little loss of fauna. 



In putting material in the funnel, lay it carefully on the 

 screen to a depth of a few inches. Moss and sod should be placed 

 upside down in a single layer on the screen. In the case of dense 

 material, pile the sample chiefly around the sides of the funnel 

 and leave an opening in the middle, as shown in fig. 7. After the 



Fig. 8. — Berlese funnels in position on rack. In this assembly, each funnel 

 rests inside a double ring of copper tubing (as on funnel at extreme lower 

 left) through which flows live steam. The steam produces the heat that dries 

 out the sample and drives the animals out of it. Cotton or a small rag is 

 tamped between the end of the funnel and the bottle of preservative to 

 prevent escape of specimens. 



