DISTRIBUTION OF SPORES 



111 



Open 



>f Cover- 



hundred miles from their place of origin. In conclusion it may 

 be said that ample evidence has shown that fungus spores "fly 

 through the air with the great- 

 est of ease" [Keitt (1942), Chris- closed 

 tiansen (1942), Durham (1942)]. 



Spore-trapping devices. Vari- 

 ous devices for determining the 

 presence and movement of wind- 

 borne spores have been em- 

 ployed. These techniques were 

 described and illustrated in a re- 

 port by the Committee on Appa- 

 ratus in Aerobiology ( 1 941 ) . The 

 simplest method consists of expos- 

 ing a surface coated with vaseline, 

 glvcerin, gelatin, or agar. 



Rittenberg (1939) exposed agar 

 plates on shipboard during cruises 

 in the Pacific in the area from 

 Monterey to the Cedros Islands 



and extending seaward 400 miles. 

 He entrapped such soil-borne or- 

 ganisms as Alternaria, Catenularia, 

 Cephalosporium, Cladosporium, 

 Penicillium, Spicaria, Sporotri- 

 chum, Stemphylium, and Tri- 

 choderma. . 



Some workers have employed 

 aspirators, by means of which a 

 definite volume of spore-laden air 

 is drawn through a filter of steri- 

 lized cotton or sugar crystals. 

 Others expose dishes containing 

 water or cotton batting. All de- 



Coated 

 glass 

 slide- 



Air 

 current 



i>\ 



I 



Hook or 

 handle 



Fig. 27. Schematic representa- 

 tion of "sky-hook" type of spore 

 trap. (Adapted from Meier and 

 Lindberg.) 



vices are serviceable. In order 



to keep the sticky surface directed toward the wind, the exposure 

 plates may be fastened to a weather vane or may be inclined from 

 the vertical for protection from rains. The most ingenious ap- 

 paratus used is the "sky hook," as employed by A4eier and Lind- 



