THE MICROBIOLOGY OF THE ATMOSPHERE 



Included and is safely covered by the term 'spore' (botanically : 'micro- 

 spore') ; but are pollen grains and mushroom spores microbes ? There is 

 no other commonly accepted word that covers quite what is meant by the 

 word 'spore' as used here: 'propagule', 'disseminule', 'biota', 'diaspore'? 

 We have isolated part of the continuum for study but find we are not well- 

 equipped verbally for the task of dealing with it. The microbial population 

 of the atmosphere is referred to here as the 'air-spora', using 'spora' as a 

 word analagous to 'flora' and 'fauna'. 



Botanical nomenclature has presented some difficulties: authorities 

 have not been given for specific names, and the names used by other 

 authors have usually been quoted as given in the original papers — without 

 necessarily attempting to guess what was meant, or following the nomen- 

 clature fashionable in i960. I have converted other workers' numerical 

 data to the metric system, and temperature to the Centigrade scale, to 

 aid comparison, and have moreover assessed spore concentrations on the 

 uniform basis of number per cubic metre. 



Frequently, in making general statements, I have omitted safeguarding, 

 but tedious, escape clauses: this has been done to spare the reader who 

 will understand that biological generalizations aboun-d in exceptions and 

 complexities. 



Interpretations in this book are mostly my own responsibility, but I 

 am grateful for help received from many people during its preparation. 

 In particular I offer my thanks to the following : G. Samuel and W. Buddin 

 for introducing me to dispersal problems in the field; F. C. Bawden for 

 encouragement in the study of aerobiology and for reading this book in 

 manuscript; E. C. Large for advice on planning the book; D. A. Boalch 

 (and many other librarians) for continual help with the literature; 

 members of the British Mycological Society for named specimens of 

 fungi, and H. L. K. Whitehouse for mosses; A. Home, V. Stansfield, 

 and F. D. Cowland for photography; R. Adams, G. C. Ainsworth, J. R. D. 

 Francis, E. J. Guthrie, Elizabeth D. Hamilton, J. M. Hirst, C. T. Ingold, 

 C. G. Johnson, F. T. Last, Kate Maunsell, T. Sreeramulu, and O. J. 

 Stedman for discussion and help with aerobiological problems and 

 applications; Audrey Baker, Beatrice E. Allard, and Marie T. Seabrook 

 for clerical assistance; and Maureen E. Bunce for experimental help, 

 revision of the manuscript, and preparation of many of the illustrations 

 — especially the paintings for Plates i, 5, 6, and 7. I also wish to thank 

 authors, editors, and publishers for permission to copy illustrations 

 which are acknowledged in the text. Finally, fi)r the calculations involved 

 in Figs. 24 to 27, and for those chapters needing the help of a mathema- 

 tician, I have been fortunate in having the constant advice and willing help 

 of my wife, Margaret F. Gregory, to whom I am most deeply grateful. 



Rothamsted Experimental Station Philip H. Gregory 



Harpenden^ Herts., England. 

 September, i960. 



vi 



