SUMMARY. 99 



conditions for the growth of the fungus occur. In many cases the 

 fungus never develops further until the infected portion of the host 

 dies. The development of the fungus in seeds as in the case of cotton 

 and bean is also evidently a special feature of Glomerella to insure 

 its passing the winter and reaching the new crop. In nature the 

 perithecial form, as in the case of many other pyrenomycetes, develops 

 normally only after the death of the host tissues. 



(12) The experiments of Scott, Rolfs, and others have shown that 

 the diseases of apples and citrus fruits caused by Glomerella can be 

 satisfactorily controlled by spraying with Bordeaux mixture. It is 

 probable that this method can be successfully used in the preven- 

 tion of the diseases of other plants caused by this fungus. The 

 selection of fungus-free seed is also an effective method of reducing 

 loss from disease, as shown by Barre for cotton and Whetzel for 

 beans. Eradication and destruction of dead and diseased parts of 

 infected plants are also important. The selection and breeding of 

 resistant varieties may also be practicable in some cases, as indi- 

 cated by the work of Bain and Essary with clover. 



252 



