THE BACTERIAL DISEASE OE COKX 



209 



mass of the mycelium, from which they readily separate. 

 They serve to spread the disease during a limited time 

 ill summer, but are supposed not to survive the winter. 

 The blackish winter spores (called by botanists the 

 teleuto-spores) are decidedly different in structure and 

 appearance from the others. A cross section of a corn 

 leaf through one of the blackish pustules is represented 

 at o.^ Fig. 86. As will be seen, the spores are borne on 

 stout stalks, to which they remain attached, c. The 

 spores themselves are so divided by a partition across the 

 middle that they are practically double ; each part can 

 germiuate independently of the other. These spores 

 survive the winter. 



Treatment. — As already intimated, no practical 

 remedy is known for this disease : and, fortunately, 

 none as yet is seriously needed. A more extended dis- 

 cussion of this malady is published in the IbST report of 

 the Department of Agriculture (pp. 389-391). 



The Bacterial Disease of Corn 



In 1889 Professor T. J. Burrill, of the University 

 of Illinois, announced the discovery of a peculiar malady 

 of Indian corn, which he had proven was due to the 

 presence of bacteria. The disease was then prevalent 

 over a considerable area in Illinois, and investigations 

 since have indicated that it does much damage — often 

 not understood, or else attributed to other causes — over 

 a large portion of the corn-growing region of the West. 

 As the disease is an obscure one, not easily recognized or 

 described, Professor Burrill's account of its appearance 

 is quoted below at length. 



External Manifestations. — The first indication 

 of this disease in a field of corn, as noticed in ordinary 

 observation, is the dwarfed condition of the young 

 plants. This commonly occurs in spots of various sizes, 

 from a few square rods, to an acre or more, and often, 

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