SUBJECT INDEX 



Tricoconis, 119 



Trigloclun, pollination of, 42 



Triphragmium ulmariae, 210 



Tripsacum, 189 



Trisettini, pollination of, 42 



Tristan da Cunha, 186 



Triticum, pollination of, 42 



Tropopause, 23, Fig. 3, 24-29 



Troposphere, 23, 24-29 



Tuhercularia vulgaris, 208 



Turbulence, 25-27, 47-50 



Turbulent boundary layer, Fig. 3, 23, 25, 26 



— deposition, 68, 72, 83, 84 



Turgid cells, discharge by rounding-off, 37 

 Tvarminne, Finland, 150 

 Tylostonia, bellows mechanism of, 35 

 Typha angustifolia, 15 



— latifolia, 15 

 Typhaceae, pollination in, 41 



Ulmiis glabra, 16 



— pollen, 43, 127, 180, 212 

 Ultra-microscope, 90 



violet radiation, 192, 193 



Umbelliferae, pollen of, 127, 212 

 Under-dispersion, 165 

 Underground railways, 160 

 Upper-air sampling, 93, 94 



air spora, 134-47 



Uredospores, 72, 82, 118-20, 123 

 Urocystis agropyri, 210 

 Uromyces, 137 



— phaseoli, 16 

 Urtica dioica, 212 



— pollination of, 43, 106, 117, 123, 127 

 U.S.S.R., migration of rusts in, 188 

 Ustilago, 35, 82, loi, 106, 114, 116, 118, 120, 



123, 135, 142, 151, 152, 210 



— nuda, 152 



— perennans, impaction efficiency, 62, 63, 71, 

 86 



— tritici, 17, 177 



— zeae, 17 



Ventilation turn-over, 155, 156 

 Venturia, 96, 120, 122, 137 

 Vertical concentration gradient, 131-3, 137, 

 138. 



— cylinder sampler, 94 



— slides, impaction on, 64-72 

 Verticillium, 139, 141, 142 



— albo-atrum, 35 



Viabilitv of spores in the atmosphere, 190-3, 



198 

 Vibrio, no 



Viciafaba, 74, 75, 165 

 Viruses and air dispersal, 33, 158 

 Visual identification, 207, Pis. 5, 6, 7 

 Volvox, 149 

 Vorticella-Uke ciliates, 149 



Warsaw, 153 



Washington, D.C., 137 



Water needed for active dispersal, 36 



Weather, effect on the air-spora, 120, 122, 



123 

 Weddell Sea, 128 

 Weed pollens, periodicity of, 117 

 WhirHng arm samplers, 103 

 White-pine blister-rust, see Croiiartiiini ribicola 

 Width of trace on cylinders, 63 

 Wind-cups, 35 

 — pollination, 2, 34, 40 

 tunnel studies of deposition, etc., 61-65, 



Fig. II 

 Windscale accident, 183 

 Winnipeg, 141 

 Workshops, the air-spora of. t6o 



Xant Ilium commune, 16 

 Xylaria polymorpha, 208 



Yeasts in air, 112, 126, 136, 139, 141, 142, 145 



— in rain, 149 



— take-off mechanisms of, 3'! 



Valley, effect of width on rust incidence, 185 

 Velocity of deposition, Vg, 77 



Zea mays, 16, 42, 130, 1S9 



245 



