208 TEXT-BOOK OF FUNGI 



example. Some saprophytic species of Polyporus are also 

 destructive to worked wood. 



Members of the animal kingdom are by no means 

 exempt from the attacks of fungi. Insects are perhaps the 

 greatest sufferers, and more especially in the larval con- 

 dition are destroyed in immense numbers. The various 

 species of Cordyceps confine their attention to insects ; 

 after infection, the larva, or in some instances the perfect 

 condition of the insect, continues to live for some time ; 

 finally it succumbs, and its body becomes filled with a 

 dense mass of interwoven hyphae, a sclerotium in fact. In 

 due course the exterior of the mummified insect becomes 

 covered with the conidial form of the fungus constitut- 

 ing the form-genus Isaria and at a still later stage the 

 ascigerous condition is developed under the form of one 

 or more club-shaped bodies. The dead bodies of larvae, 

 more or less buried in moss and bearing the pale yellow 

 silky clusters of conidia, or the crimson club-shaped asco- 

 phores of Cordyceps militaris, are not uncommon in this 

 country. A species of Saprokgnia is the cause of the 

 destructive salmon disease ; other kinds of fish also suffer. 



Human beings are by no means exempt from diseases 

 due to fungi, and in too many instances suffer from such 

 at a very early age. ' Thrush,' the white pellicle on a 

 baby's tongue, gums, etc., is caused by Oidium albicans. 

 ' Ringworm ' is caused by Achorion Schoenknii. Numerous 

 other examples are on record. 



Brefeld,/.-^. Schles. Ges. VaterL Cultur, Zool.-Bot., 1900, 

 p. 17. 



Cattaneo e Oliva, 'Dei Miceti trovati sul corpo umano,' 

 Archiv. Lab. Bot. Critt., Pavia, 5, p. 48 (ii 



