I02 Flag^ Smut of Wheat. 



and that is probably because they are more likely to be in- 

 fected by the spores at the proper time for germination. Late 

 wheats do not suit our conditions ; so that the selection should 

 be made from early maturing varieties. 

 Now that a certain measure o_' success has been gained in securing rust 

 and bunt-resisting wheats, similar methods may be adopted with regard to 

 Flag smut, and a smut-free late wheat, crossed with a susceptible early 

 variety, might lead to earUness combined with smut-resistance. 



Summary. 



Flag smut of wheat does not infect rye, and rye smut does not infect 

 wheat : so the form occurring on wheat is a distinct biological species, and is, 

 therefore, named Urocystis tritici, Koern. 



Infection occurs in the seedling stage, also when the young shoots are 

 being formed, but not when the plant is above ground, and this infection may 

 arise either from spores adhering to the surface of the grain or from diseased 

 straw or fragments of flag in the soil. The spores may persist and retain 

 their vitality on wheaten chaff, and soil containing manure from horses and 

 cattle fed on diseased hay is capable of infecting the wheat plant. 



The adherence of the smutted soil to the feet of men and animals may 

 cause it to be transported from one place to another, and agricultural imple- 

 ments also scatter and carry it. 



Since this smut is only known to attack wheat, a change of crop will 

 evidently tend to starve it out ; but as it is not known how long the spores 

 retain their germinating power, the nature and extent of the rotation cannot 

 yet be -determined. 



