1898.] PUBLIC DOCUMENT — No. 33. 63 



distortion in shape seen in affected specimens. Upon this 

 host the fungus forms little pustules just beneath the sur- 

 face, finally breaking out into the air as tubular projections. 

 In these are formed the yellow spores of this stage, called 

 cecidia. These spores are unable to infest quinces again, 

 but upon cedar trees begin the development of a new gen- 

 eration of "apples," which will in turn produce teleuto 

 spores the following spring. 



Treatment. — It is not often that the damage caused by 

 this disease is of great extent. Sometimes, however, it 

 becomes sufficiently troublesome to make it worth while to 

 attempt to repress it. It is evident that the most vulnera- 

 ble point of the fungus causing the trouble lies in its inabil- 

 ity to reproduce itself continuously upon the quince. The 

 most direct method of treatment, therefore, is to extermi- 

 nate all white and red cedars and junipers from the vicinity 

 of the orchard, and cut off all affected parts of the fruit 

 trees, or entirely destroy badly affected ones. This, for 

 various reasons, however, may not always be possible or 

 desirable. As to spraying methods, it has been found quite 

 effective to spray with Bordeaux mixture two or three times 

 during the spring, especially during or just after rainy 

 weather, when the spores are being disseminated. It may 

 also be possible sometimes to remove affected twigs of 

 cedar and juniper trees before the spores have been pro- 

 duced. 



This same fungus has also been unusually abundant during 

 the past season upon the fruit of various species of Cratffi- 

 gus (hawthorne), accompanied by an equal abundance of 

 the closely related species, Gymnosporangium globosum, 

 upon the leaves. We have also noticed these or related 

 species upon the fruit of the Japanese quince (Cydonia 

 Japonica) and mountain ash (Pirus Americana). 



The Brown Rot of Stone Fruits. 



{Monilia fructigena. Pers.) 



This well-known disease found in the past summer just 



the conditions suited to its best development, and the peach, 



plum and cherry crops suffered in consequence. The dis- 



