44 



THE ART OF MAKING MICROSCOPE SLIDES 



Mites 



Fig. 21. Berlese funnel in use. 



the funnel must be sealed to prevent the 

 more active forms from working their way 

 out of the tube. 



After the mass has been placed in posi- 

 tion a small lamp, certainly not of more 

 than 15 watts, is mounted in any kind of a 

 reflector some distance above the material. 

 The animals in the material, therefore, 

 find themselves surrounded by heat at the 

 sides and plagued with hght froju above. 

 As all of these animals are photophobic, 



they tend to move toward the lowest point 

 of the mass from which they drop down 

 the tube into the funnel. By this means it 

 is possible in 10 or 15 minutes to collect 

 the whole fauna from a large handful of 

 any organic material which would, by any 

 other means, take several hours to search. 

 The use of the funnel is not, of course, con- 

 fined to moss but may be used for hay, 

 straw, shredded bark, or any other mate- 

 rial from which small arthropods are cus- 



