BURT THELEPHORACEAE OF NORTH AMERICA. VII 6Z1 



fixed and preserved for a cytological study of Septobasidium 

 during spore production. Discussion of the systematic rela- 

 tionships of Septobasidium may well await the completion 

 of such study. 



The species of Septobasidium are tropical or subtropical. 

 Extreme northern stations, based on specimens examined 

 by the writer, are London, Ontario, Canada, and Madison, 

 Wisconsin — both are stations for S. pseudopedicellatum, 

 which is the most frequent species of the United States. 



With regard to the biology of Septobasidium, several speci- 

 mens of this genus — usually of ^S'. pseudopedicellatum — have 

 been noted by their respective collectors as occurring espe- 

 cially on plants badly affected by scale insects. Other speci- 

 mens show scale insects numerous about the fructification 

 and overrun by it. Fetch ^ in a note on the biology of Sep- 

 tobasidium states that from examination of a long series of 

 specimens, it has been determined that these fungi are par- 

 asitic on colonies of scale insects which they overgrow and 

 destroy completely, and that these fungi live, not on secre- 

 tions of the insects, but upon the insects themselves. 



In addition to independent observations on the association 

 of Septobasidium with scale insects, other facts tending to 

 show an entomogenous adaptation of Septobasidium are the 

 following : 



(1) All species of Septobasidium known to the writer 

 occur only on living branches or leaves, and in no instance 

 has there been penetration by the fungus through the epi- 

 dermis or bark into the living tissues of the substratum, 

 or any injury or deformation or gall response by the branch 

 or leaf. 



(2) Spores are produced by S. pseudopedicellatum , in the 

 region from North Carolina and Alabama to Porto Rico, in 

 May when young colonies of the scale insects are forming. 

 Mr. Seagle wrote to me that the old fructifications of S. 

 pseudopedicellatum disappear from his apple trees in North 

 Carolina in late spring and in early summer, and new fruc- 



^Ann. Bot. 25:843. 1911. 



