MYXOGASTRES 527 



gardens, all diseased plants should be either burned or deeply 

 buried, and not given to pigs, etc., or thrown on the manure 

 heap. 



Again, it must be remembered, that land having produced 

 a diseased crop is certain to be infected, and furthermore the 

 parasite present in the soil retains its vitality for five or more 

 years, unless treated with lime, hence the removal of such 

 infected soil to other fields and portions of land on the 

 wheels of carts, or on various implements, boots, etc., should 

 be guarded against as far as practicable. A proper rota- 

 tion of crops checks the disease, as does the removal of all 

 cruciferous weeds, charlock, etc., on which the parasite may 

 sustain itself during the interval between turnip crops. 



Board of Agric. Leaflet, No. 77 (1902). 

 Eycleshymer, Journ. Mycol., 8, p. 79. 

 Halsted, Amer. Gard., 19, p. 375. 

 Massee, Proc. Roy. Soc, 57 (1895). 

 Nawaschin, S., Flora, 86, p. 404 (1899). 

 Ward, M., Diseases of Plants, p. 47. 

 Woronin, Pringsh. Jahrb., n (1878). 



Crown gall. -This disease, caused by Dendrophagus globosus 

 (Tourney), is reckoned as a serious disease in some parts of 

 the United States. It is considered probable that it is identical 

 with the disease known in Germany and some other European 

 countries as wurzelkropf, but this is not definitely proved. 

 It has not been recorded in this country. The injury results 

 in the formation of swellings at the crown of the root, and 

 also on the smaller roots. The swellings are at first small, 

 but gradually increase in size until they attain the dimensions 

 of a cricket-ball, or in some instances much larger. All kinds 

 of fruit-trees, also the vine, are liable to attack. The Plas- 

 modium of the fungus lives in the substance of the gall, and 

 under favourable conditions comes to the surface, where it 

 forms deep orange, sessile, globose sporangia, about 1 mm. 

 diameter ; spores globose, orange-yellow, 1 5-3 \i diam., 

 capillitium scanty. 



The disease is spread by infected nurseries sending trees 

 into different parts of the country, also by diseased trees 

 being distributed for firewood. 



Tourney's suggested remedies are as follows : 



So little is as yet known regarding this disease, that few 

 systematic attempts have been made to treat it by the 



