FUNGOID PESTS OF TIMBEE 141 



myceKum may break away and grow into a 

 new plant) or by means of spores, which function 

 as the seeds of higher plants, though the two are 

 not analogous. 



For the most part fungi are classified accord- 

 ing to the structure and arrangement of their 

 spores. They may be borne on basidia, httle 

 stalked structures which themselves are situated 

 upon gills as in the edible mushroom, or within 

 pores, as -in the case of the bracket fungus 

 (Polyporus). Or they may be borne in httle 

 sacs, known as asci, and the asci again may be 

 exposed or concealed in cup-shaped cavities 

 known as perithecia. Yet another form of 

 spore is borne in chains upon a small stalk ; 

 these chains of spores are known as conidia 

 and, like the asci, they may be exposed or borne 

 in hollows, known as pycnidia. Whatever the 

 nature of the spore, of its formation and growth, 

 it is the reproductive organ upon which the 

 fungus depends for its spread. All spores are 

 very light and are easily blown about by the 

 wind. Whenever a spore falls upon a suitable 

 host it germinates, sending out a tube which 

 in time becomes the mycelium of a fungus. 

 Small wonder then that, owing to their small 

 size and easy transportation, fungus spores form 

 a ready means of distribution for the majority 

 of injurious pests. 



