16 . 
that the host cells usually exhibit a capacity for dissemination 
outside the laboratory that is similar to that for bacteria". Because 
of specialisation in the reproductive cycles the fungal spore is highly 
adapted for dispersal by air, water and animals. In addition, the 
organisms themselves are known to produce unusual substances - antibiotics, 
alkaloids and other highly toxic agents. Moreover, industrial antibiotic 
producing strains have been shown to contain large amounts of double 
stranded R!!A virus. Thus, even at this speculative stage we urge that 
these organisms be used with greater stringency than prokaryotes. 
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