PROCEEDINGS OF THE ANNUAL MEETING 



179 



They will, liowevor, grow readily into the young twigs of red cedjir, and 

 these produce what finally develop into cedar-apples. These curved, 

 orange-colored arms consist of clusters of slender, fiexible stems, each 

 of which bears a two-celled or double spore. On some wet day these 







l-\ 



Wi 



Plate III. 



A large and small cedar-apple in May. as swollen when wet, often two inches in diameter. 

 One arm of cedar-apple much enlarged. 



Portion of a section of arm, highly magnified, showing two-celled spores. 

 Two spores more highly magnified, and at the left several spores germiijating and pro- 

 ducing sporidia which are ready to grow and produce rust on leaves of apple trees. 

 Leaves of apples affected by rust caught from cedar apples. 

 Six of the cluster-cups as seen on the lower sides of the leaves of an apple. 



7. A section of an affected leaf of an apple tree, much thickened in the region of some 



cluster-cups. 



8. Section of empty cluster-cup very much enlarged. 



germinate in a few hours and produce little arms, on the ends of which 

 are borne very small secondary spores or sporidia, and these may be 

 carried by wind to neighboring apple trees, where they germinate and 

 enter the tender leaves to start colonies of cluster-cups. After shedding 



