THE ASCOSPORE AND OTHER FUNGI 



245 



infection do likewise. Consequently it is evident that the 

 threads of the fungus grow along with the new growth of 

 the branch. The best remedy is to cut the branch off, some- 

 what below the point of infection, thus removing the dis- 

 eased tissues. 



APPLE SCAB AND PEAR SCAB 



The Apple Scab is one of the most familiar fungous 

 diseases. It appears as black spots, upon the surface of the 

 apple, and also 

 upon the leaves. 

 The spores of 

 the fungus that 

 causes the dis- 

 ease are pro- 

 duced in great 

 abundance on 

 these blackened 

 spots. They are 

 scattered far and 

 wide by wind and 

 rain. Those that 

 lodge upon the leaves or fruits of apple trees germinate 

 during moist weather by sending out little tubes and thus 

 start the disease anew. 



The growing portion of the fungus consists of brown- 

 ish cells. After a time the cells multiply and push out- 

 ward, exposing a surface in which the small oval spores 

 develop. These spores live through the winter on the 

 bark, twigs, and stored apples, as well as on the fallen 

 leaves and fruit. 



The Apple Scab fungus not only causes the apples to 

 appear unsightly and injures them for food, but it also pre- 



APPLE SCAB 



