MILDEW AND BRAND. 45 



CHAPTER lY. 



MILDEW AND BRAND. 



DR. WITHERING^S ^'Arrangement of British 

 Plants '^ in 1818 reached its sixth edition. This- 

 is less than half a century ago_, and yet the whole 

 number of species of Fungi described in that edition 

 was only 564, of which three hundred were included 

 under the old genus Agaricus. Less than eighty of 

 the more minute species of Fungi, but few of which 

 deserve the name of microscopic, were supposed to 

 contain all then known of these wonderful organ- 

 isms. Since that period, microscopes have be- 

 come very different instruments, and one result has 

 been the increase of Withering^s 564 species of 

 British Fungi to the 2,479 enumerated in the 

 ''Index Fungorum Britannicorum.^^ By far the- 

 greater number of species thus added depend for 

 their specific, and often generic characters, upon 

 microscopical examination. The proportion which 

 the cryptogamic section bears to the phanerogamic 

 in our local Floras before 1818, now almost invol- 

 untarily causes a smile. Even such authors as were 

 supposed to pay the greatest possible respect to the- 

 lower orders of plants could never present an equal 

 number of pages devoted to them, as to the higher 

 orders. Relhan, for instance, only occupies one- 



