THE UPPER-AIR SPORA 



TABLE XXIII 



ANALYSIS OF PADY & KELLY's (1954) DATA ON TWO RETURN FLIGHTS 

 OVER THE NORTH ATLANTIC, SHOWING CONCENTRATIONS PER CUBIC METRE 

 OVER LAND, AND MEAN CONCENTRATION OF BACTERIA ANT) FUNGI IN AIR- 

 MASSES 0\TR OCEAN 



Bacteria 



Fungi 



The bacteria obtained on these flights were classified as: 



The fungi identified occurred in the following percentages (mean of 

 the two flights): Cladosporium^ 82-3; Alternaria, 2-6; Pulhilaria, 2-3; 

 yeasts, 2-1; Penicillium, i-6; Botrytis, 1-5; Stemphylium, i-i; non-sporu- 

 lating colonies, 3-2 per cent. Of these, Alternaria^ yeasts, Botrytis^ and 

 Penicillium were noted as more abundant in tropical air, whereas Stem- 

 phylinm, PuUularia, Fusarimn, and Papularia were more abundant in polar 

 air. Sporormia was found several times, always in polar air. Many other 

 fungi occurred in small numbers. 



Among the many interesting results that stand out clearly from these 

 flights is the discovery that viable bacteria and fungi occur at an altitude 

 of 3,000 metres in air masses all the way across the North Atlantic, 

 though the bacteria were so few that some samples of about 2 cubic metres 

 appeared to be entirely devoid of them. There was, however, no gradual 

 diminution with the distance from land. Cladosporium is the dominant 

 fungus over the oceans, as it is also over land, but it probably loses viability 

 as the air mass travels. 



K 145 



