THE OLIVE tubercle: TYPE 



391 



being greatly distorted and reduced in number while the paren- 

 chyma is in excess as in crown gall. Often a large part of the 

 tumor, as in Fig. 306, is composed of bark, and then the tumor 

 is of a soft "cheesy" character. The structure of a young tumor 

 developing on the under surface of a leaf is shown in Fig. 307. 



Fig. 298. Fig. 299. 



Fig. 298. — Pure-culture inoculations of Bacterium savastanoi in olive shoots 

 in 1903. Left-hand shoot Gentile, others Nevadillo Blanco. Time, 57 days. 

 The organism used was plated from a California olive knot. J-^ nat. size. 



Fig. 299. — Pure-culture inoculation of Bacteriimi savastanoi made in 1910, 

 on an olive shoot at X, which became dwarfed and died. The lower tumors are 

 later surface infections derived from bacteria that oozed from A". Photographed 

 in 1912. 2^ nat. size. 



This disease has been known since the time of Theophrastus 

 (Savastano) and occurs in all olive-growing regions around the 

 Mediterranean, and also in California, Argentina (Haumann- 

 Merck) and other parts of the world. 



This same disease, or a very similar one, occurs on the 

 European ash {Fraxinus excelsior) in France, Germany, Austria 



