FUNGOUS DISEASES. Ill 



developed which, in turn, become swollen and dis- 

 torted into various shapes. Of the most interest in 

 this connection is the cause of the peculiar develop- 

 ment and consequent destruction of the infested 

 plants. As in nearly all instances of similar abnor- 

 mal structures, these root galls were long ago 

 assigned to insects. A careful study of their devel- 

 opment failed, however, to convict any species or 

 group of insects of these depredations, and after 

 much speculation, and no end of articles in the agri- 

 cultural, journals and elsewhere, it was reserved for 

 M. Woronin, a European botanist, after three years 

 of painstaking and exhaustive study, to explain the 

 nature of the subject before us. Instead of any 

 insects being the cause, although such decaying 

 masses usually become the breeding places for them, 

 Woronin found that a low form of fungus was con- 

 stantly present in the affected parts. This parasitic 

 organism is only seen with the higher powers of the 

 compound microscope. The family of fungi to 

 which it belongs, namely, the slime molds, is widely 

 distinct from the mildews, rusts and smuts. The 

 life of the obscure club root parasite has been traced 

 from its appearance in the root as a slime in certain 

 cells to the formation of multitudes of spores in 

 these same cells. By the decay of the roots, which 

 takes place rapidly, and with much offensive odor, 

 the spores are set free. in the soil. These spores there 

 o-erminate by producing moving bodies capable of 

 penetrating, or being absorbed by the thin walls of 

 the hairs and other superficial cells of the roots. The 

 soil becomes diseased in the sense that the germs, 

 formed in the swellings and other distortions of the 

 roots, are set free, and the earth holds them for an 



