LOSSES DUE TO CROWN-GALL. 189 



1907, inclusive, the bushes were always sick, and have during the whole time borne 

 either no fruit whatever or a very scanty crop. 



These plants were an ever-bearing variety from Denmark. 

 In August, 1907, Wulff also found a bad outbreak of the disease in 

 middle Sweden near Orebro: 



Here about 800 bushes of Red Hornet and about 100 of Superlative were attacked. 

 The first-named bushes were planted in 1901, had borne very well during the first 

 years, and appeared entirely normal. In 1906 the first symptoms of the disease were 

 discovered, and in consequence of this no crop was borne in the summers of 1906 

 and 1907. 



In the next paragraph Wulff speaks of the disease as ''very inju- 

 rious to raspberry culture" everywhere in Sweden where it has 

 appeared. He also brings forward evidence to show that frost injuries 

 have nothing to do with its appearance, and cites similar statements 

 by Blankenhorn and ISIiihlhauser (vide Sorauer I, 596) with respect 

 to the grape gall. Wulff 's own statement is: 



Bei meinem Untersuchungen der Himbeerkallose habe ich niemals auch nur die 

 geringsten Andeutungen von Frostbeschadigungen entdecken konnen. 



Concerning the origin of the disease neither in this paper nor a 

 second one (Weitere Studien iiber die Kalluskrankheit des Himbeer- 

 strauches, Arkiv fiir Botanik, Bd. 8, No. 15, Upsala, 1909) does he 

 reach any positive conclusion, other than that he has not been able 

 to find in the fresh overgrowths any parasitic organism and is inclined 

 to ascribe them to excessive nitrogen nutrition and excessive water 

 supply. 



Lawrence (Some Important Plant Diseases of Washington, Bull. 

 No. 83, 1907) shows a very interesting figure of blackberr}^ canes 

 split open by the growths arising from within and says that in the 

 State of Washington the disease is very destructive to the Snyder, 

 and that occasionally Kittatinny and Himalaya Giant are badly 

 infected, while Erie, Early Harvest, and Evergreen are not seriously 

 injured. 



He has also observed the disease to be severe on the red raspberry, 

 especially the form growing on roots and crowns. 



Glissow has attributed a gall on the blackberry in England to a 

 fungus, Coniothyrium tumefaciens n. sp. 



THE ROSE. 



Occasionally the disease is very prevalent on the roots of roses 

 grown in the hothouse, and skilled gardeners are generally of the 

 opinion that the galls are seriously injurious, reducing the size of the 

 plants, the amount of foliage, and the vigor of the flowers. Here 

 again exact comparative studies are wanting. It must be obvious, 

 however, in the case of a small plant like the hothouse rose, that the 



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