174 BOTANICAL GAZETTE. __ [ August, 
find them, and to ask what are the inferences which we are. 
the species of a single genus or order. It is almost unneces-_ 
Sary to cite instances of the two kinds of parasites propels 
since you will at once call to mind Penicillium and other 
vommon moulds which grow as saprophytes on an ae 
variety of substances; while we have as illustrations ie true 
