124 



PRACTICAL BOTAN Y. 



The Ustilago maydis, the smut that attacks Indian Corn, 

 will serve as an example of these plants. It attacks the 

 corn in different places the stem, leaf, tassel, and the 

 ear. The diseased portions of the corn grow to ah abnor- 

 mal size, and all the tissues within the epidermis gradually 

 give place to the developing spores. These spores form 



FIG. H9. Smut spores germinating. (Kellerman.) 



in such quantity that the epidermis is finally broken 

 through, and the black, smutlike spores are scattered to 

 the wind. 



References for Reading. Goebel's " Classification of Plants," pp. 

 85-88 ; Cooke's " Introduction to the Study of the Fungi," pp. 251- 

 258; Vines' "Text-Book of Botany," pp. 308-310; Bennett and Mur- 

 ray's " Cryptogamic Botany," pp. 349-352. 



