MICHIGAN ACADEMY OF SCIENCE. 105 



portance for the persisteuce of the fuugiiH. in a locality where the mum- 

 mied fruits are not destroyed. If the weather for one season were so 

 unfavorable for the fungus that no plums rotted and hence no new 

 sclerotia were formed, the old mummies would still carry the fungus 

 over to the next season, and we do not know that even two years is 

 the final limit beyond which the fungus cannot reproduce itself. The 

 importance of destroying the old mummied fruits, whether on the 

 ground or on the tree, is manifest. E. F. Smith long ago pointed out 

 that the mummies which hang on the tree from one season to the next 

 are often capable of producing a new crop of conidia in the spring. 



Univ. of Michigan, April 1910. 

 14 



