LIST OF TABLES 



PAGE 



I Observed terminal velocities of pollens and spores . .16-17 



II Pollen distribution at different altitudes .... 20 



III Size of 5f/z<^7 pollen at different altitudes .... 21 



IV Typical characteristics of anemophilous and entomophilous 



plants ......... 40 



V Results of dispersal of spores of r/7/^?/fl frtr/V5 . . ■ 5^ 

 VI Dispersal of mixed spores of Tilletia caries and Bovista plumhea 53 

 VII Calculation of parameters of Sutton's diffusion equation from 



Stepanov's data ........ 54 



VIII Observed values of parameters in Sutton's diffusion equation 



from experiments on spore dispersal . . . -55 

 IX Efficiency of deposition on inclined slides in turbulent wind- 

 tunnel . . . . . . . . -71 



X Efficiency of deposition of Lycopodium spores on upper and 

 lower surfaces of potato and broad-bean leaflets in turbulent 

 wind-tunnel . . . . . . . -75 



XI Deposition on grass of Lycopodium spores activated with 



iodine- 13 1 ......... 78 



XII Deposition of spores on ground ..... 79 



XIII Observed values of p and Vg for Lycopodium spores on hori- 



zontal microscope slide in wind-tunnel .... 80 



XIV Percentage of total spores liberated near ground-level that were 



estimated to have been deposited on ground in open-air tests 80 

 XV Number of Lycopodium spores deposited on upper and lower 



surfaces of horizontal traps ...... 84 



XVI Average density of spore deposit from three types of trap 2 m. 



above ground ........ loi 



XVII Estimated detection thresholds of concentration of Hirst trap 



and sticky microscope slides inclined at 45° . . .106 

 XVIII Means of monthly mean numbers of bacteria and moulds per 



cubic metre of outdoor air in Paris . . . .111 



XIX Total number of pollen grains and spores per cubic metre in 



oak-birch wood . . . . . . . • 115 



XX Diurnal periodicity in the air-spora on land . . 1 16-17 



XXI Temperatures at which highest concentrations were recorded 120 



XXII Numbers of microbes and distance from land . . . 126 



XXIII Analysis of Pady and Kelly's (1954) data on two return flights 



over the North Atlantic . . . . -145 



XXIV Geometric means of ratios of catches by rain-trap to dry-trap 151 



xiv 



